Without your giving more information, it's hard to explain specifics but in your posts (on 2 different discussions there), you complained because you felt that you'd overpaid for items that the seller dropshipped from Walmart. (By "overpaid," I mean that you paid a premium over what the item(s) sold for at Walmart.)
If you complained to ebay about dropshipping and didn't like their response, the problem is that they allow dropshipping. (There are some categories of items where dropshipping raises red flags but for the items you purchased, there aren't red flags.)
Understand that there's a value to being able to sit at your computer in the comfort of your own home, search and find just what you're looking for, buy and pay and in a few days, the mailman will deliver that item. You never have to leave home because the other seller does your shopping for you. He uses his car, puts wear and tear on it, drives from store to store shopping, spends hours photographing, listing and writing descriptions and waits for buyers. Once those buyers come, he has to pack, print shipping labels and ship those items.
And on top of it all, he pays ebay (or whatever site) and paypal fees for listing there.
So, yeah, you'll pay more than if you did your own running around yourself going to however many stores it takes to find the in-stock items.
I guess I just don't understand your issues. If you don't want to pay more than retail, go shopping. If you want the convenience of having a personal shopper, you're going to pay for that convenience.