1P

So I have a booking for 2 days and 10 hours at a cost of $148.

My flights are messed up, and I am rerouted on another airline, meaning I actually arrive four and a half hours earlier than I thought — i.e. 8pm instead of 12:30am.

How much would it cost to amend the reservation? The new charge would be $274! That's an extra $126 for just a few additional hours, or an extra 85%.

OK, if I cancel the reservation and start over? The same price: $274.

How can anyone justify this sort of thing? No wonder I don't use Avis much these days.

WIRunner

Could you provide rental days? And more specific times? It could have been a weekend rate or discounted rate that you may have qualified for that don't any longer.

CodeAdam10

Don't make any changes. Just arrive early and pick up your car. You're already paying for 3 days so it won't add any extra cost. Let the clerk know you'll return the car early (ie: by 8pm) accordingly which you will as you only needed it for 2 1/2 days which is counted as 3 full days regardless.

Doc Savage

It's not unusual to have rates go up as you get closer to the trip. Try Priceline, etc. if you are sure there will be no further schedule changes, or just other companies.

I have run into situations where a res after midnight was a lot cheaper than one before, and had to wait for 30 min to save the $.

As for showing up early, I'd recommend a second "safety reservation" somewhere in case the staff are overly rule conscious.

1P

Was going to be 00:30 on Thursday morning, bringing car back 10:00am Saturday morning. Changed it to 8:00pm Wednesday evening, same return on Sat morning. Daily rate skyrocketed as a result.

sdsearch

Ah, you went from a weekendish rate (which start Thursday) and switched to a middle-of-the-week rate (for rentals starting on Wednesday). That's likely the issue.

Anyway, what you can do is reserve the car for the earliest time you expect to possibly arrive (with change of flight), but put your actual flight info in. Then, if your flight changes, notify them of the new flight number, but don't change the reservation. Bingo. If you arrive on the originally scheduled flight, your car will be ready. If you arrive early (especially if you aren't able to notify them hours in advance), you may have to deal with the counter for a few minutes (in case your car wasn't prepared yet because they were waiting for your later flight), but your rate will not change.

They key to all this is that arrival flight info in the reservation is what's used to prepeare you car (if you specify the arrival flight, that is), while the pickup time is used for the billing. And the other key is that changing arrival flight info (but nothing else) in your reservation costs nothing, while changing anything else in your reservation causes it to be repriced.