According to the price guide a new copy should sell for at least $44.95:
http://videogames.pricecharting.com/.../full-throttle
However, I'm not sure how being sealed effects the price or by how much. Keep it though becuase you never know how the price will change. I bought Keio's Flying Squadron for the Sega CD when it was $70 just a couple of years ago and it's now valued at over $100.