Man, I know how you feel. I've been thinking about it for 2.5 years and now that I'm getting close to deciding for it, some folks have made me take a second look which has, in turn, forced me to reconsider.
Replying to ya might help me streamline my own thought process since they're similar, so bear with me.
Reasons to get a HT:
1. Get laid more
2. Self-esteem
That's pretty much it as far as I can see, really. I'd have put self-esteem in #1, but let's be honest. Which is more important? Hair is purely cosmetic so this is a vanity thing, but at the same time - that's very important. Self-confidence affects everything about your life.
So, think about this in detail.
1. Do you get laid regularly? I don't mean beg-for-a-VD type of regularly, but if you're not in a long term relationship then do you bag 2-3 girls/year? (If you are in a relationship then stop reading. It doesn't concern you. She likes you the way you are, so what do you care if you have no hair, 3 nipples or a tail?) If you do, then you don't *need* a HT, but want one. Get one if you have money lying around, but don't worry about it too much.
2. Do you think you're good-looking? Look in the mirror, like what you see? If you don't, chalk one up for the HT. If you're generally happy, then you don't need one.
How's your confidence? Have you ever gone into a bar with a buddy or 2 and played the numbers game? It's a fun game in which the buddy selects a girl for you, then you walk over, chat her up & try to get her phone number. She might tell you to piss off (rare), ignore you (less rare) or chat you two hit it off (more common than you'd think). Do you know that the fairer sex likes you and your company, at least most of the time? If you do then you don't need a HT.
Remember that self-confidence is in your head, not on it. Ever been with a really hot girl and after the first month or so, when the looks thing wore off, realize that you really don't want to be spending time with her? On the other hand, ever been with an average-looking girl - few extra pounds, not your type, peg leg - and realized: wow, a diamond in the rough! If you hyave, then you know the other side of it.
I'm getting wordy. Think about why you want a transplant. Be honest. Then, think about whether the reason for it is lack of hair, or something else masquarading underneath that. And at the end of it all, if you realize that a new hairline is what you really want, then hey man - good luck. And post some pictures so we can see!