is there any thing to watch out for on a 14,000 hr 770d I found one at a good price, looks in nice shape
That's getting to be plenty of hours, I would not expect that to be a low maintenance machine unless you have a laundry list of service records. If I were looking at something like that I'd spend the money and have a mechanic come out and thoroughly inspect it . I don't know anything specifically about those machines but everything wears out eventually and the newer this stuff gets the more expense it seems to get to do component replacements. I've heard horror stories about transmission and drive line overhauls that used to cost $20k on older machines going over $40k on C series JD's. It only takes one of those to blow any savings you might think your getting over spending the money up front on a lower hour machine.