If you don't mind planning a year's travel in advance, you might look into economy RTW fares that cover up to 16 segments over a 12 month period. The fares require you to cross both the Pacific and Atlantic oceans in the same direction, and end in the same country where you began. Both Star Alliance and Oneworld offer these products, with the Star RTWs having maximum mileage limits while the Oneworld ones are priced based on how many continents you touch, from 3 to 6.

Both alliances' RTWs are priced VERY differently depending on where you begin and end travel, as well as their own mileage or continent limits. For example, a 4-continent Oneworld RTW in economy with travel beginning and ending in the US has a base price of $5374, or around $336 per segment. However, the same ticket with travel starting and ending in Norway costs $1956, or $122 per segment. Yes, you'd have to get to Oslo to start the trip and return to the US following it, but in the meantime you could rack up a good many miles, and hit some places where budget accommodations are more plentiful. Note taxes and airline fees are on top of these base prices, usually in the 10% - 20% range depending on the selected airports and airlines.

By starting overseas, you can turn the one ticket into at least 2, but as many as 3 to 5 separate holidays, by using your home city as a stopover. For example, this imaginary Oneworld 4-continent RTW starting and ending in Norway would allow you to fly home via Buenos Aires (or could be Santiago, or Rio, or Lima, wherever) then use the six allowed segments within North America (which includes the Caribbean and Central America) for separate short-term trips, or longer ones if you want. You'd conclude the trip with stops in Asia and eastern Europe before ending back in Norway.

Or this one would take you to South Africa, then across to Australia, New Zealand and Fiji, before returning you to the US for some domestic trips. Then ultimately you'd cross the Atlantic for some time in Eastern Europe before again ending in Norway.

The RTWs include baggage allowances and offer normal FF perks. If you're willing to plan several months' (to a year's) travel in advance, they can be terrific value.