I shipped my T5 a few years back, from Indiana to Florida. I believe I went UPS, and it was under 100$. Is it an AOD or T5? For some reason I remember my T5 being right under the weight cut-off limit, so an AOD is probably going to be more expensive than what I payed.
The MOST important thing is making sure you pack it very well. Make a cradle for it from 2x4s that will slide into the box. No cardboard box will hold a trans by itself.
I've shipped lots of freight and found Old Dominion and R&L Carriers are the cheapest and most reliable with the best record for not damaging stuff. Make sure you call them for a rate quote because when you do not have an account with them you get a 60%-65% discount usually, and tell them you don't have an account. (Don't ask me how in the world you get a discount for NOT having an account with them, but that's how they do it.)