Well, the game is not that rare. You can find a used copy for cheap, but a brand new one can go up to 80 or maybe more. Last night I saw one on ebay going for like 77.00 with 10 hours left to end the auction.
[quote name='zegota']Wow, is it really that rare? I guess I shouldn't let my nephew borrow it.[/QUOTE]
For what ever reason some of the GBA versions sell for a lot. I remember there being a plethora of these at Circuit City before they went under. A sealed copy is always going to sell more too and it also depends on the person on how much it's worth to them.
(22) Fallout 3 Game of the Year Edition (Sealed) - $10 (96) Castlevania Circle of the Moon (Complete) - $3
(97) Sword of Mana (Complete) - $2
(95) Castlevania (Complete) - $2