I paid about 8,500 for the surgery and I think I'll be very happy in a few weeks. I'm still bruised and swollen so can't really see the final result yet. I had two transplant surgeries 10 years ago (with Dr. Rassman) for temple areas and sides of hairline (both original surgery and FUE) and the only thing I would tell you to take into consideration is that you'll need more than one HT surgery to achieve the right density (a good Dr. will tell you the same thing) AND the transplanted hair can be coarser and kinkier when it grows back.
Since you sound like you wanna lower your hairline quite a bit, the hairline lowering surgery would probably be cheaper and quicker in the long run.