Amazon displays prices from third party sellers if they themselves don't have it in stock. so if you saw a gameboy or a loving original xbox console (which is worth like at most $20, seriously), chances are you saw some wacko third party seller trying to make a deal off of idiots who think these are vintage.
$430 for pokemon red? $300 for LoZ? $111 for loving tetris?
"insanely high"? get real.
i'd love to buy an SP from you, but no more than $40 at max. this stuff's old and not diamond-valuable like amazon ripoff-wannabes put them up to be.
edit: wrong word, max not min for the SP.