What kind of computer do you have available - older, newer, much memory or little, so forth? What operating system? And are you in the US? We know the Craigslist suggestion for finding a tablet won't do a Brazilian or German much good :-).
And you can't get much cheaper than a pencil and a piece of paper ...
I use GIMP, have never used Photoshop but according to the experts there are some things that PS does better and also things that Gimp can do. I don't think you will be sorry trying it. If you have no artistic talent then you may have to download some of the brushes here and there in order to turn it into a stamper but pretty much anything you can draw you can put in there.
I use Inkscape for the labels though because I'm not really knocked out with how Gimp puts words on a curve.
“When it’s over and you look in the mirror, did you do the best that you were capable of? If so, the score does not matter. But if you find that you did your best you were capable of, you will find it to your liking.” -John Wooden
* My Finished Maps
* My Challenge Maps
* My deviantArt