It really depends on the GAME you are getting graded. The biggest problem is weighting the expectation of value on the chance that there will be more copies out there with higher grades.
Unless the game was ultra rare I wouldn't bother grading unless you are certain it was going to get a 85+ or more. However considering the cost of grading in the USA is much lower I would have less reservations on doing it.
Rips to the seal will have more impact on the grade than surface marks. Prices for grading can be found here:
http://www.vggrader.com/submission_packagedpricing.aspx
For a game like this and the fact you are in USA, I would say that you can't really go wrong with grading it. However don't expect a huge increase in value ( if any) for quite some time. What you will have is a game that will have a grade fixed and be fully protected. So peace of mind.