Shopping eBay stores

I have found a couple of eBay stores that I would like to do some business with. But I am kind of hesitant about a colleague told me a horse story about his dealing with an eBay store. He was telling me that an eBay store sold him a high-end home audio receiver he said he picked it up for a little cheaper than what some of the local retailers sold for. When he got it they shipped him the wrong model and he had to fight with this company for over two months before they would recognize their issue and at that point they said they were all sold out and he cared return it for a full refund. But it took him another three months before he actually saw the money credited back to his PayPal account. He said it got to open point where he almost had to file a grievance in small claims court against this company. I know that this is not the norm for eBay stores but because I am so new to this eBay site I was wondering if there is any recommendations of what I should or should not do worse things to look at before making my final purchase. If any of my eBay friends have any suggestions on how I should protect myself please let me know.

Sincerely your friend

Cal Bears 510