You bought a $5 game. Most services have flat fees. Shipping doesn't scale linearly. These things all added up.
I buy lots of shit from YAJ, usually Laserdiscs, which are very heavy. Two LDs and packaging is easily over half a kg. You have to take major advantage of the warehouse systems of these places. Use seamail if you are cheap. Pack the boxes logically. It takes, whatever, $10 or so to get a game shipped from Japan. However it might only take $11 to ship two. However if you need to move a few hundreds lbs of shit at once then you'll be moving into freight territory which causes the price to spike per lbs again until you start to become limited by the price of a shipping container. For example, it costs $3500 to ship a Supra, but it costs the same to ship two Suzuki Altos because they'll fit in one container and containers are charged the same regardless of weight. This same concept continues even into space exploration. If you want to send a rat into space it can be squeezed onto someone else's shuttle for one price but if you want to ship a 100' mecha rat you're better off chartering your own heavy moving rocket.
Once the inefficiency one one system starts to spike you'll probably notice alternatives. I think they actually teach that in economics courses but sometimes I wonder...
If I buy something on YAJ I expect the end price to double. Yours more than tripled so it can get better but it will always cost more than eBay for the fees and such.
Btw, Verizon now (for some reason) owns Yahoo so in the future we may be calling it VAJ. Hopefukly this won't happen. I already have that issue when talking in forums about the Volkswagon Automotive Group.