Sorry but darkslime's initial comment was what I was thinking, hahaha!!!:lol:
But I'll help you out a bit.
Obviously the condition is the most important thing - is the game complete and mint with mint box, instructions, etc.? Or cart only with a bunch of permanent marker, sticker damage, and rental stickers on it? Also remember, just because it's listed on amazon for $45, doesn't mean it's selling for $45. Could be more or less, depending on the condition, how you describe it, and where you list it.
If you throw it on amazon, be sure and select the proper COLLECTIBLE category (Collectible - Like New, Collectible - Very Good etc.) and describe it accurately, since it is obviously very collectible, out of print, and almost always you can ask substantially more for items under the Collectible subsection of the game page than the Use subsection. I always try to list EVERYTHING I sell under the Collectible section since there are almost always far fewer listings thus less competition there and the asking prices are almost always substantially higher - thus I can command a much higher selling price, even if it takes longer to sell I don't mind at all.
Otherwise, throw it on eBay with a reserve, but don't automatically expect to get $45 or guide value for it. Check out vgpc.com and rarityguide.com for rough estimates of its worth...though again, I would never ever ever pay anywhere close to rarityguide's "values" particularly for complete/mint games...but I would sell them for those amounts FLOL.