1. What amazing insurance do you have that covers hair transplants?
2. Hair transplants are far, far less invasive (and far more accurate) than a hairline advance / forehead reduction. There's often a hairline scar with HA / FR, whereas with transplants there's no noticeable difference pre- and post-surgery other than the addition of extra hair where there was once none. A good hair transplant clinic can give you a female hairline if you ask.
I went through the same thought process myself: why pay for transplants if I could get a hairline advance during FFS. Bottom line for me was that the hairline advance is often kinda clumsy and imperfect, while the transplant process is really rather delicate, accurate and artistic - you literally define your new hairline, rather than being under when it's done and not having any say in how it is shaped or how your scalp heals. Natural hair is never achieved with a sledgehammer.
If money is no issue and insurance is covering it, go for a transplant first. Of course, this assumes you don't need valuable grafts elsewhere - crown, top of your head - that a hairline advance won't cure. If it's merely a case of thickening out the temples and redefining the hairline, then transplants are a no-brainer. And if the transplants don't give you what you're looking for, have the advance. But to confuse the issue, if your areas to be transplanted are large, a hairline advance might be the way to go, followed by transplants afterwards to tidy things up and make it look natural.
It's my understanding that a transplant before a hairline advance might cut out newly-transplanted regions, but that's also clumsy surgery. An area that is already hairy doesn't need to be advanced in the first place, and raises the question as to why the surgeon would even consider removing hairy scalp.
If grafts might be so scarce that it's going to be an issue, I'd strongly suggest going to a GCS surgeon for GCS, and a dedicated FFS surgeon for FFS. That'll maximize your cosmetic results. You know the old saying, a jack of all trades is a master of none...
I think the bottom line is that an FFS surgeon will tell you that a hairline advance is the way to go, while a hair transplant clinic will tell you that transplants are the way to go. To be perfectly honest, I think you're safe no matter what you choose.
A tough choice, but one which I wished I had! Transplants are crazy expensive out of pocket, as my bank manager can attest to.
