Don't put a lot of faith in Google's recommended budget however. If it works at all, it's based on the systemwide 2% CTR which may or may not fit you. The recommended budget is usually too low for most campaigns to function effectively.
Go by what you're willing to spend but not more is the advice usually given here. Personally, I have to at least triple the recommended budget to get my ad seen everytime, even with a CTR well over 2%
patient2all