I would get the one Whirlwind linked. I have a precursur to it called the G11, which actually has 18 programmable keys. I don't need them, but they come in handy every once and a while. I like how the keys light up, and it is more sturdy than a regular keyboard. A mouse is definitely much more worth it than the keyboard, but for $50-$70, it will last you a good while. I wouldn't get any of those super fancy ones with a screen, but there are a few people out there that think it is worth it.
When I look at cost nowdays, I tend to compare stuff to alcohol. If I really wanted to, I could spend $50-$70 at a bar in one night. You add in cab fare and all that, the keyboard, which will last years, is cheaper. That is the only good thing about how expensive a night at the bar can be, it makes everything else seem a lot cheaper lol.