If the transaction is protected by eBay money back guarantee, you should be able to get a full refund.
If the seller sends you a completely different item, you should file a return claim for "item not as described" and return the item you got for a complete refund.
If the seller does not send anything, you will file a money back guarantee claim for "item not received"
They should return your money in full.
Please note, neither of these things are quick and it requires you to follow the steps outlined in the guarantee.
My suggestion to you is to find an item and a seller that looks trustworthy and meets your expectations. When you look for an item that seems "too good to be true" there is potential for issues. Check seller feedback, and in particular, look for feedback that relates to the item you are looking for.
If the seller suddenly has a bunch of high priced items that are listed for unbelievably low prices, I would run. "if it is too good to be true, it probably is too good to be true"
