If you believe your monitor is calibrated correctly, I'd recommend getting professionally created profile, for example from aforementioned Cathy. Not only it will give you a profile, that you know is correct, but also gives you instructions on how to set your color management properly. If you later decide to buy the ColorMunki, you will use it with greater confidence and knowledge how professional profiles look like.
Buying profiles is ok if you don't change inks or papers but if you want the flexibility of using several papers and canvas then the cost of the profiles goes up. Some are (or were) a lot dearer than others.
I'm happy with the colormunki so far. Speed, ease of use, and results are all quite ok.
