I just got my first snake on Sunday from petco, because they were on sale for $29.
The tanks at the petco I went to looked good. They had a light, and an under tank mat and used aspen bedding. They said they had more in the back that they weren't selling because they aren't eating.

I got the BP on Sunday and fed her on the same day they feed her (Thursay) and she ate without a problem. Overall I'm happy with my local Petco.