Looking to get my first tat.

Well, I've been reading up about it, and I'm left with just a couple questions. I decided I want a black peace sign on my left forearm, about 2 inch diameter and maybe 1/4" thickness..I'd like a ballpark figure of cost. Also, can this be done with one sitting? Lastly, what is the age requirement in Florida, I'm 18..can I get a tat without my mommy?

Oh..Also, I'd greatly appreciate if someone could recommend a place in Miami, FL. I'm in the Kendal area, thanks in advance.