Originally Posted by Elola

$114ai for a 4-day intermediate rental is a pretty darn good deal, I doubt you'll be able to get it much lower with any publicly available discounts, chances are that adding one to your reservation will recalculate your base rate to the point where it's more expensive than your current rate.

Concerning mileage, rentals of "normal" (economy-fullsize) cars are typically unlimited mileage provided you're returning to the same location where you rented, but the best way to make sure is to look up your current reservation on avis.com, there you will be able to see whether or not a mileage fee applies.