Is Earthbound worht trading for Mother 1, 2, and 3? Who gets the better deal? If guy 1 has Earthbound and Guy 2 has all japanese mothers and they both trade. Who gets the better deal?
Depends on the condition and completeness of each game.
A complete in box EarthBound usually sells for $250-$300. A stray EB cart averages about $70-100.
A complete in box MOTHER usually isn't too expensive, they go on YAJ for the equivalent of about $20-30 last I checked. Though I'm very unsure about this. I remember I got mine for 1600 yen, so that was about $20 at the time.
A complete in box MOTHER2 is about the same as MOTHER, so around $20-$30.
MOTHER3 complete in box sells in the $30-40 range.
So the whole Japanese set is worth about $70 to $100. So if you are trading just an EB cart, then you're getting a pretty fair trade, money-wise. If your EB is a complete in box set, no way.
But consider personal value as well. If you only have one EB cart and don't know Japanese/don't have the Japanese systems to play the MOTHER games, then that might be enough reason not to trade.