Honestly, the at home stuff is incredibly easy. My mom started dyeing her hair pretty young because she had a lot of grays and didn't like it. I frequently come over and dye her hair and drink wine : p. It's much easier if you can have someone else do it because there's less chance that you'll stain your skin.
Hers comes in a box and you mix the two ingredients (the box comes with gloves) and just completely coat your hair, attempting to not get it on your neck or face. The box will tell you how long to leave it on and then you just take a shower.
I think going to a hair dresser can actually get pretty expensive. My sister has dyed her hair a few times and it was around 65 dollars. My mom dyes her hair every month (some people go longer, her hair grows fast). The box of hair dye she gets is only 10 bucks.
You could always find a hairdresser and then try dyeing it at home. If you didn't like it, the hairdresser could easily fix it. : )