This is going to FAIL miserably in the long run. I wonder just how many hoops you have to jump through on this.
So say you buy all your christmas gifts for people, pay with paypal and then when the after christmas sales come around get back the difference in price.
Or better yet, buy from your own company and then drop the price and get money back..... this is so open for fraud.
This "refund" better NOT be coming from the original sellers.