The eBay fee is 9.0% on an auction, plus $0.30 + 2.9% PayPal fee on the gross. If you are a Power Seller or do a fixed price listing this could be slightly less, but if not, $0.30 + 11.9% of $158 is $19.10. $19.10 + $11.30 postage + $2 coin bags and packing tape = $32.40. $158 - $32.40 - $100 = $25.60. Once you start deducting the gas to acquire the $500 in source cents (assuming 20% yield), the time to sort them, gas to transport the zincs for return, and time to package them, you could have $10 in gas and 20 hours of time invested, in which case you would be making $0.78 per hour.