How much something like that cost?
Asking for a friend...
Now I'm not sure how serious you are, but...
Pretty expensive, depending on the method used to harvest the follicles and who is doing the surgery. Different doctors charge different rates, but as a general rule the FUT strip harvesting procedure is cheapest, and FUE (individual follicular units) is more expensive. Those are the two big ones, and there are variations of these methods.
There's really no reason to go for FUE over FUT before you've really begun to exhaust your donor supply though. It's just more expensive for nothing, really (in my opinion). There's a scar with the FUT procedure but proper stitching techniques make them almost unnoticeable and unless you shave the back of your head really short (as in a short buzz cut) you never have to worry about it being detected.
FUE does have its place, though. It's the only way to get other body hair (beard and maybe chest are really the only ones worth using for the most part) for transplantation.
Overall the price depends on the number of grafts, obviously, which will depend on just how bald you are. Typically in the US prices for FUT surgery range from $3-$6 per graft, whereas FUE costs $6-$10 per graft. Those prices are a ton cheaper overseas, for instance there's an actual proper clinic in India that has prices as low as $1.50 per graft for FUE. It's crazy how much cheaper it is, and the surgeons are actually certified by hair restoration boards that certify US doctors, so it's worth looking into.
Here in the US, expect to pay at least $10,000 for a decent amount of grafts with a reputable doctor. That's just one procedure, more procedures until your donor supply is exhausted is something a lot of people do after they get their first transplant. It's really come a long way from how crappy it used to look when you transplanted your hair. Just look at before and after pictures from decent clinics and judge for yourself. And it's your own hair, I don't really understand the stigma behind it. In my opinion all it really shows is that you obviously have a lot of money to be blowing it on a hair transplant (or two, or three) and you end up with a pretty decent head of hair all things considered if you actually go to reputable doctors.
Ask me how I know all this...