Had a look around for the new Goldeneye game today and the cheapest I could find it for was £17.99 at Amazon. Can't see anyone beating prices like that.
Check out steam. They usually have some great sales. here is a website that lists the current sales. BTW they are doing a holiday sale right and have some good games for very cheap.
Soft modding a Wii is an easy process. The amount of command line screens can be intimidating, but it's automated for the most part. Search for a tutorial on YouTube and get it done so you can play "backups".