I agree with the idea that if you can't afford to pay it off early then you should buy used. You must be a very careful shopper but, there are used units out there in good shape ! You just have to do your research and know what to look for.
Buying a TT on a 12 year loan is asking for trouble. How can you know if you will still be making this much money in 12 years ? What if things change that you can not predict ?
People have short memories. Doesn't anyone remember a few years ago when people were buying houses on the cheap thinking that they could flip them for more money? Then the bottom dropped out and it all went bad.
Doesn't anyone remember Enron a few years before that ?
It is OK to make payments. But, 12 years is just to long for a TT.