So in conclusion, I guess the one thing we can all agree on is that the OP should have removed all price stickers..

No one got ripped off, the buyer only paid about $1.00 more than what the seller paid. If the buyer had paid $34.95 then found out that the seller had only paid $15.90 that would have been ripping the buyer off.

The mistake that the seller made was quoting the original RRP and leaving the sticker on with the discounted price..

As someone else pointed out, after the PayPal fees etc the seller actually lost money