Need some opinions...girl stuff
If you buy it for your current size it will end up not fitting you in a few months. If you buy it one size smaller it won't fit you for awhile, then you might lose more weight and it won't fit you later down the road. If you buy it many sizes smaller you run the risk of it NEVER fitting.
I'm in the same boat ... I have no idea what size my body is going to end up being. All I can do is wait and see. I'm personally going to wait until my current clothing no longer fits and for every pound I lose I sock away a 5 bucks ... by the time I lose 100 pounds I'll have $500 towards new clothes. (yeah, I'm a cheapskate, lol)
Considering that I went from a size 28/30 to a size 16 in 8 months time (I am a size 12/14 now in pants and a Med/Lrg in shirts), I wouldn't even bother spending that much money. I totally fell in love with our local thrift stores... 
There will come a point where you will look at something an think, "Too cute!! But if I buy it, I'll only wear it for 5 or 6 weeks. What's the point of spending that much money?"
