In my opinon and experience it's very important to have meds to hand and perhaps bettas are prone to the disease the meds treated. For instnace I think it would be very wise to buy ich meds if buying clown loaches or hatchetfish.
I believe it is always better to be prepared for disaster than to grope around afterward. In the case of fish, diseases can get out of hand pretty fast. And, by the way, Petsmart has a 100% garantee on all pet supplies. The person could always return their decoration or meds. (even if it is used!)
didn't know that................. 
