eBay: NO Insertion Fee and NO Final Value Fee on ONE item listed through mobile app Feb 12-14 YMMV

not too sure why people is bashing amazon/ebay/paypal.
roughly 10% commission is not that bad for access to buyers across the US (or globe)
commission rate is not random, they figure this stuff out. if commission is lower, then neither buyer nor seller would be protected from potential fraud.
I know people will say "They only protect the buyer and screw the seller". But if you read their seller protection terms, its clear if you don't follow their rules then you only leave yourself vulnerable even if you "think" you did everything right.

For popular electronics (ipods, cameras, gaming consoles, earphones etc.) generally best to go with amazon 8% fee

for unique/rare items, laptops/desktops, broken electronics, collectibles, etc. generally best to go with ebay 12.9% fee for auction, less for buy it now.

ebay and amazon amazon combined, I have sold maybe 1700 items over the past 27 months?
few bumps on the road, but never once was it not solved to both the buyer and seller's satisfaction.

hint: don't give in to obvious scammer, but when buyers is genuinely concerned, have a problem, want to return or what not, you want to work with them until they are also satisfied even if you are 100% right in the first place.
if customer wants a $15 refund because of whatever, you negotiate with them, don't right out tell them NO. poor feedback is not worth few dollars saved.

always accept returns within reasonable time frame. If buyer's fault, they pay for shipping both ways. if seller's fault, you pay for shipping both ways. if you can sell it in the same condition, do not charge restocking fee or that ticks off the buyer.
if its just buyer's remorse and return condition difers then sent, then you should only charge restocking fee equal to the differences between market value and paid value.

also protect yourself against potential losses
for buyers less then 30 feedbacks on ebay, I add signature confirmation to purchases over $100
everyone else I add signature confirmation to purchases over $200 (ebay rules)

for amazon.
I add signature confirmation to people living in apt, sending to business address, or purchases over $250