Hey LunchBox-
I have a Hanna Checker, which I saw at first glance for $33 on Amazon, and plan on a couple extra dollars for buffering solutions.
I might have a different Hanna Checker model, or maybe I bought from the wrong site a few years ago, but it seems to me that the price of the pH unit I purchased was ~$100.
I have no idea if that unit would work for soil testing. I didn't thing the same unit would work for both, so if it will, I hope someone will chime in with more information and how to use it for soil.