Just like Maggot said... depends on the store.
I am a complete newbie with any tank based pet but luckily I found these here forums as I was going through the buying process.
So, in an attempt to do my due diligence, I went to every pet store in a 20 mile radius with included a Petco and 2 PetSmart stores.
Here were my observations:
1. Prices between all places varied somewhat drastically. One brand name part might be cheaper at the local pet shop and others were cheaper at the chain stores.
2. The local pet stores (except for one) all seemed dirty with poor looking reptiles in general. Not to mention, their cricket setups were horrid, etc. The chain stores seemed to be a little neater.
3. The "Except for One" store I mentioned was a breeder of fine geckos. Animals looked great but were pricey (in the $150+ range each). Not what I was looking to spend for a beginners setup.
4. Petco was clean but the staff was just plain dumb on the subject ("It's special sand so the geckos can never get impacted").
5. One PetSmart seemed okay but still pretty clueless. We winded up buying an Exo-Terra tank there because, well, the size we wanted was in stock.
6. The second PetSmart store was awesome. But for one reason only... the guy helping us was an avid hobbiest. He was very familiar with this website and all the literature I had been reading etc. etc. We left with 3 hatchlings who are extremely healthy 2 months later.
So, the key is, learn enough from here so you feel comfortable then go buy the right geckos for your goals (pets, breeding, etc) anywhere that has what you want in a healthy animal. If you can get to a show (like a ReptiCon) that is a great idea but ordering online seems to be without issues too.