Matty Collector eBay confusion

I have been watching ebay because I have some Matty Collector stuff I want to try to gauge value because I have some items I am going to have to sell pretty soon. I am just curious why 2 different listings of the same item being sold by 2 different sellers has widely fluctuating prices. 1 is open-box and is currently being bid up above $600 when the exact same item sealed is available via a buy it now for much less (<500). Both domestic US sellers, both high feedback ratings, shipping cost is a non factor. The people currently bidding 6+ could get it cheaper via Buy It Now. Is there some other factor I am unaware of (like reprint versions or something) I purposely did not link the items because I don’t want to even give the appearance of promoting them being as I am not affiliated with the particular items or parties in question. I am just curious since I really don’t know the market on these collectibles.

There are 3 kinds of prices on eBay. First, what the item typically sells for. Second, an inflated and overpriced item. Third, an absolute deal. An item priced way below what it sells for. It’s rare but they do pop up. The easiest way to gauge what something is worth is looking at the completed listings for that item. Comparing several auctions the item actually sold for will give you an average of what it should sell for. Hope this is helpful.

What item is going for $600?

It no longer is, I have screenshots showing it though. I think I have figured out what is going on. I think some sellers are using new accounts to place shill bids on the competition in order to drive the price up and make their auction more appealing. I might just try selling what I have here. In the case I described above it was the Matty PKE.

There’s a ton of shiling going on in the collectible markets right now, especially hot ones like Ghostbusters. Report anything suspicious - eBay eventually nukes the accounts. You’ll see a lot of 1-10 feedback accounts doing this kind of thing. It’s one of the reasons the PKE is so damned expensive right now - someone’s sitting on a lot of them.

I occassionally browse ebay or amazon because would like to invest on other collectibles aside from just Funko Pop but I need to replace my battered fender flares for now.