It's good to do your strategic planning in advance but book your actual travel plans somewhat on the fly. I think Priceline offers good value as long as you're willing to accept its limitations. I also think, however, that hotel loyalty programs can offer some good value as well.

First, in doing your research, do some dummy bookings at various hotel websites or on third-party sites, like Travelocity and Expedia. When doing these bookings, check weekend as well as weekday rates. I think you'll find that some of the conventional wisdom about the price of hotels in big cities versus small cities evaporates when you get to weekends. I've found some very good deals at nice hotels in San Francisco on weekends that beat the prices I'd be likely to find for similar or lesser hotels in a smaller town, such as Wilmington, NC. I suspect that because business travel drives a lot of big city hotel occupancy, rates fall on Fridays and Saturdays and may go back up on Sunday night in anticipation of the coming work week. This principle just doesn't seem as strong in small towns, other than tourist small towns where in-season prices tend to stay high on weekends and weekdays. Although you might want to keep your travel plans flexible, I think you'll find that a sound strategy involves trying to hit big cities mostly on weekends and smaller towns during the week while avoiding, if possible, the peak season in any places that are mostly tourist destinations (think Santa Cruz or Monterey in the summer). The rate information you get will be supplemental information you can use if you decide to use Priceline to book hotels.

Second, you might consider outlying properties, both in small towns and in big cities, depending on the transportation options available. For instance, I know that it's possible to get some reasonably priced accommodations around San Francisco International Airport that are located relatively close to BART lines. Although I think you can find a good hotel at a good price in the city on weekends, if your travels took you to SF during the week, this option might provide you with a reasonably priced hotel and access to San Francisco without fighting the nightmare of driving and parking in the city. At the same time, in smaller towns that are tourist oriented, you may find an outlying hotel that is reasonably priced as well. For instance, there is a Red Roof Inn in Watsonville, California, located almost midway between Monterey and Santa Cruz, that probably won't cost more than $80 a night and that can serve as a base for going to those two small towns.

Third, if you decide to go the hotel loyalty route, there may be some benefit in pursuing a two-tier strategy. Pick a lower-end chain, such as Choice or Wyndham, as well as a higher-end brand, such as IHG, Hilton, Hyatt, or SPG. Then balance your stays between the two, depending on the price that meets your $100/day budget. Keep in mind that most of the promotions these chains run tend to vary on a quarterly basis so whatever benefit you may gain on one portion of your trip, you may find will change in no more than three months.

For instance, using my own two-tier strategy with Choice and SPG as an example, I can currently earn 8000 Choice points with every two stays (with a stay defined as one night in most Choice hotels although as two nights in certain of their cheaper or extended-stay properties). With my elite level, I'm currently limited to receiving four of these point accumulations (which Choice loosely refers to as free nights, but which may not equal a free night at a majority of their properties); higher elite levels may receive up to ten of these accumulations. With SPG, I can qualify for a free night with every three stays (and as opposed to the Choice program, truly a free night) at a number of their resort properties (about 200 worldwide) but not all of their hotels. And, unlike Choice, there is no limit on the number of free resort nights I can earn. The current programs run until late July/August and then a new round of promotions with different terms will begin that will probably take you to Halloween/Thanksgiving.

Choice's network of hotels (as well as Wyndham's) are found in many small towns where SPG, IHG, Hyatt, and Hilton would never make an appearance. In addition, you're very likely to find that their hotels will charge from $60-100 per night, allowing you to apply the balance saved to pay for hotels above your $100 average when you need to stay at Hyatt, Hilton, IHG, or SPG properties. And one final thing about Choice: although we think of them as mostly an American chain, they have properties all over the world, and you'd be surprised at how many of them you can get for an 8000-point award redemption (check out Paris, Prague, Rome, and Tokyo as examples).

Fourth, if you go the loyalty route, I'd check out some of the loyalty credit cards. Although the sign up bonuses for these credit cards won't generally get you more than two to five free nights, those are free nights--again money that you can use in other places in your budget to cover the increased cost of a hotel in a bigger city or for a splurge. In addition, most of these cards tend to confer some level of status within the hotel's elite structure, sometimes meaning that you earn hotel points faster (for instance, at SPG hotels, gold and higher levels earn 3 points per dollar spent on hotel reservations and incidental hotel charges, such as meals at the hotel restaurant, rather than the standard 2).

Fifth, your computer (iPhone, iPad, etc.) is your friend, not just now as you prepare for your trip but as you travel. For your current planning, check the hotel sub-forums here on FT; these are a wealth of information, both about the general operations of the chain as well as, in some instances, specific properties. While you're traveling, unless it's a busy season in a particular area (another thing you can probably research using your computer), I tend to make my leisure travel reservations on the fly. Especially for lower-end chains, I recommend checking a site like TripAdvisor before making a reservation. Just as with any Internet opinion site, you have to learn to weigh the opinions and take some with a grain of salt, but if you regularly see a comment, such as "in bad area of town," in a review, you'll probably want to avoid it. Your computer will also help you learn of new promotions. For instance, SPG is currently running a promotion with Foursquare giving you a bonus of 250 points each time you check in during a stay at one of their hotels. Depending on how lucky you are with the rate you get at the hotel, this bonus may meet or exceed the points you've earned from paying for the hotel.

Sixth, don't completely rule out non-hotel accommodations that may prove cheaper. In my travels in Ireland and Scotland, I've found many B&Bs as good as or better than many hotels for about half the price. I don't use hostels, but my sister had a very good experience at one she used in Dublin this past March that cost her about a third the price of the hotel I stayed in last summer. I don't think these alternatives are as good in this country (B&Bs tend to be overpriced here in comparison with the ones I've used in Ireland and Scotland while hostels tend to be much less comfortable and safe here than their European counterparts).

I hope my post has raised more questions than it has answered because that's its intent. There's no way to convey all of the subtleties of travel programs in a long web article, much less a forum post (what's a "stay" as opposed to a "night"?). I'm not suggesting following my strategy to the letter. I am suggesting that you look at all of the chain hotel websites, both to get a feel for their pricing and for their award structure. Play with Priceline a bit. You may like it, you may not. Figure out what kinds of hotels work best for you and your girlfriend. I think you've set a reasonable goal for the amount you want to pay for hotel accommodations. Further research will help you figure out how to stay under your budget with some occasional splurges included (with the current SPG promo, I'll end up converting each set of three $70 per night Sheraton/Aloft/Four Points stays into a $550 per night room at the Turnberry Resort in Scotland in August--that's a splurge I'm looking forward to).

Good luck!