If you're absolutely certain that you want to do the following two things:

• Buy Monster Hunter Tri
  
• Buy $10 worth of other things from Amazon in the near future

Good news! The retailer is now offering a free $10 credit with purchases of both the standard edition and Classic Controller Pro bundle of Monster Hunter Tri. For some reason, it's not listed on Amazon's $10 Bonus Offers page, but the game's page mentions the deal.

In addition to that bonus, the standard edition is currently priced at $44.99, so you'd effectively be getting Monster Hunter for $34.99.

[Via GoNintendo]