My Key Loan was for $60K and the payments are coming out to be about $450 per month, but I think they can be refinanced as the anonoman said. The main thing that kills us all is that hefty interest that starts accruing right away, ouch
As for ATP, I went to FSI myself and overall had a fairly positive experience but to be honest, I would look long and hard and carefully gauge the two before making a decision. If I had to do it all over again, I may well have gotten my private at a local FBO then done that $35K program at ATP, it's called the Airline Career Pilot Program.
I've heard nothing but good things about ATP, as for the intensity and speed, but might be a good prep for the way initial indoctrination and stands classes are done at the airlines. Look up posts at their forum, especially from pscraig, he started at FSI like me but left early on and went to ATP instead.
Now I haven't been there myself, but it seems if you pass the writtens on your own with help from Gleims or King courses then u can show up for 3-4 months and have a blast at ATP chocking up Seminole X-Country time coast to coast, even if a lot of it is safety pilot time it's still loggable total time.
AT FSI, u get comprehensive ground schools and lots of extras like the spatial disorientation training in the GATT and the spin training in the ZLIN, but their CIME program doesn't even include your Comm Single Engine, or any of your CFI tickets and it is liable to go well over the advertised amount if u don't stick closely to the 141 syllabus progress they expect.
I've been told ATP is very good about sticking to costs, u get tons of mutli-engine cross country time and r even liable to get some actual IFR on those long trips. And most of all is the chance to instruct there later, no long waiting list like at FSI. I was considering ATP's CFI program but they won't let grads from that program instruct at ATP.
Hope this helps.