I used to work in a tattoo parlour for a couple years, a couple years back ...
If your anywhere near London, I've got a couple buddies who have done my tattoo's (Half Sleeve, full Chest, legs, back, etc ...)
Depending on what it is, If its elaborate design, with crazy colours .. be VERY weary of where and who does the tattoo ...
If you pick price over talent, thats bad news, I've had many a cover up from my younger days(im only 29, but, yeah) ..
those dumb tattoo's were bad decisions, cause i didn't have the coin to pay for an actual professional ...
so, i guess yeah, i know a couple ppl who do them, I have done them before, but I'm terrible, and i have a couple I've done on myself to prove actually how brutal I am at it .. lol. ....
Some advice from someone who is riddled in them, choose wisely, look at portfolios of the artist(note, ARTIST), every artist has a style, choose a artist with a style that best suits the design...
some of my stuff is on this site ...