Just as long as you know you won't get your money back...
I am finding that now. I spent $, but really, when it comes to selling it on, how much you spent doesn't make as much difference as you would think.
Not hard to maintain. I would sugesst when you get the car though, make sure you find out when the timing belt, pulleys, tensioner kit, top n bottom seals, water pump etc were last changed. Thats important to know (usually 100,000k service). If you need to do all this, could cost you anywhere from 800 onwards, depending where you go. If its an importer or dealer, I would check the belt at least anyway, regardless of what they say, as it has probably had the k's wound back and you can't talk to the previous owner. You may also want to check castor rods, bushes etc.
GTR is 4wd, you don't want that. You will have a very hard time learning to drift in a 4wd. That said, you can disable the front end if you really wanted. R34 GT-T is heavier than 32, but with any rear wheel drive car you can do some degree of drifting...
You seem pretty set on this drifting idea, is this to eventually compete, or just for personal use, n maybe a few friday nights at driftland? If you want to build a 'hectic' drift car you are much better off starting with a silvia/200sx or 180sx as I said before