1.8T Ins and Outs

Firstly hello everyone! I'm Mike and new to the forum!

Right, I am looking for a 1.8T A3 but I want to know the in's and out's of what I should be looking for excatly. Such as is it ok to by one with 100k miles? What problems occur with an A3? The general in's and out's!
Also how much I should be paying for one in good nick? Any general information will be helpful.

Thanks in advance look forward to your replys