I am 27 years old and Fall 2012 is the first time I'm applying to DPT programs. I've wanted to do this for awhile, though circumstance did not allow me to commit to the application process until last year. What ever you're doing, make sure your heart is in it. If you're just throwing around the idea, I would pursue a PTA program. But if you have been in the industry and have work experience, go for DPT.
How many of the typical prerequisites do you have covered? If time is an issue and you don't have many prereq's I would say check out PTA programs. That is not to say you can go for your DPT later. Debt will not be an issue. Anyone will let you sign your life away for $80k if you get into a program [with a co-signer]. Dream big...