Don't be a sucker.
If you remove the feedback they have no reason to refund you.
Go here:
http://resolutioncenter.ebay.ca/
and open a Dispute.
You will have to return the item to the seller with Confirmation of Delivery. If the seller is overseas this will be very expensive ($40 or more).
Changing your mind is not a valid reason for leaving a neutral or negative feedback.It's your problem, not the sellers.
Read the listing. Read the shipping cost. Don't bid until you have done both and then add the asking price + the shipping cost together.
If the price is too high, DON'T BID!!