I have a tattooed wedding ring (DH has a matching one) I have another small tattoo "elsewhere" that only my spouse and my gynecologist have seen. I keep thinking about more, but I don't for 2 reasons:
First, the only place that won't continue to sag is the lower back, and I'm really not enthused about getting a "tramp stamp". saw a woman who had a tattoo on the side of her belly and probably before she had kids, it was a circle. It isn't anymore...
Second, if I had that much "spare money" laying around, I'd buy fabric with it!