Hair...where to begin?
Male pattern baldness, on the level of individual follicles, varies. Some follicles are not producing hair (or producing only very thin hair) because DHT is forcing them into some level of dormancy. Some follicles are not producing hair because DHT has had such a profound effect that it's actually permanently killed the follicle. The former can sometimes be resurrected via HRT, finasteride, minoxidil etc. The latter are done for.
If MPB is creeping in, stop or slow it immediately via the use of finasteride (Propecia) and minoxidil (Rogaine) - your doc can provide the finasteride (try to get the generic tablet and cut it rather than the far more expensive and smaller brand name tablet - make sure you ask him or her for the generic), and the minoxidil is available fairly cheaply in generic form at any pharmacy. This'll buy you time to get on HRT if you're not already there.
Those areas that are only thinning will probably be most likely to regrow; the bald ones that have been bald for a while are less likely to ever regrow. For me, I was thinning on the top of my head, and with HRT, finasteride and minoxidil, the results haven't been too bad. A lot of the thickness might be due to the fact that my hair is just longer now, but at least it's not getting worse. My temples had been totally bald for a while, and nothing I threw at those areas has had much of an effect whatsoever - those follicles are dead.
I did have a hair transplant in those areas however. As of right now, the jury's still out on whether it was a success or not, and it'll take a year or so before I'll be able to make that call. It was not cheap, but to me, it was worth it (I hope!) to try and repair my natural hair. I was able to request that my hairline be reshaped a little so that they didn't reconstruct the old male hairline I had, but instead something slightly more feminine - any reasonable transplant team should be able to feminize your hairline. Again, not much regrowth from the transplanted areas yet, but it's still early days.
Now, considering the fact that I'll be pursuing FFS in the future, and considering the fact that adding a hairline advance to the FFS package will be a simple and fairly cheap thing to do, I might end up (like many girls do) having my hairline further feminized in a more aggressive surgical manner. I'm slightly worried about scarring along the hairline, which could be covered by more transplants - although the transplant procedure was one I found a little gruesome to sit through to be honest - but to me, having my own hair is worth fighting for at this point in time.
So to answer your questions in a roundabout way: yes, transplants can be used to alter your hairline and make it more feminine. Is it cost-effective? Depends on how extensive the transplant will be, and having a hairline advance rather than a hair transplant may be a better route - look into both. If you're worried about MPB, then please get on the meds to stop or slow it - the longer you wait, the harder and more expensive it'll be to correct it in the future.
One afterthought to throw in there: when you're out and about in the near future, look at women whose hair is pulled back. Many have hairlines that I'd consider similar to guys with thinning or bald temples. Your MPB may not be as unfeminine as you think it is, and simply growing out your hair, styling it in a feminine way, and working on other aspects of your appearance might be sufficient.
