A lot of hatred towards Petco... I have had good success with them. Most of the time when I get fish from them, I order them and pick it up when the shipment comes in while it is still in the bag. I bought a fire shrimp from there with a coupon, sale AND girlfriend's employee discount and it wound up being around $8. He lived for about a month but fell victim to an open filter tube. When he died, I bought two cleaner shrimp from them. This particular store has terrible water but if you acclimate properly and your water is good, there should not be a problem.
Half of my fish came from Petco and almost all of my inverts came from Petco. The key with stores like Petco is to test THEIR water along with yours before you decide how to acclimate. My shrimp were all acclimated over about three hours through a very slow drip. Their water had low PH, low salinity and very high nitrate/phosphate.