Absolutely acclimate. Why spend all that money to end up having to flush or put in a compost?
While a lot of fish stores don't drip acclimate their new arrivals due to the amount of fish they have going into tanks all at once, they have a lot less to lose than the consumer does, as they are paying wholesale prices and we are paying their mark up.
Awhile back I started getting to know when my LFS was ordering and would buy the fish I wanted before he temperature acclimated them to his tanks.
Since my LFS gives me a pretty good guarantee and he knows my fish get drip acclimated he will still stand behind his guarantee even though they aren't in his QT tank and in mine.
By buying the things I want for the tank as they arrive, I get an additional savings too, as my LFS seems to like not having to do the work.
Just my 2¢ on the subject.
Denise M.