ok... the title is "How much do tattoos hurt?" so I'm going to answer that.
I have two tattoo's (well, one complete and one not even close to finished, pictures below):
My first tattoo, a blue dragon perched on a rock with clouds
My latest tattoo.. a predator mask with an alien claw, completely original work. There's still roughly $1000 to do to this piece.
Now you ask about the pain. Honestly, it all depends where you get it done. My first tattoo was done on my left shoulder blade, and even though it was a little uncomfortable, it was nothing bad at all, just like a tingly sensation the whole time. My second tattoo is on the right side of my chest, with the alien claw going across my collar bone. The tattoo goes down ALMOST to my right nipple.
The latest tattoo hurt more than anything. I was surprised that getting tattooed on my collar bone wasn't as bad as I thought it would be, it was actually more of a tickle sensation than anything. But once my artist was shading the bottom of the mask, which is very close to the nipple, it REALLY hurt.
So in conclusion, it just all depends where you get it done. Different parts of the body will feel a LOT different than certain others.