Don't buy it
140,000+k's no way. That Calais has done far to many k's. Few tricks I've learnt when buying. Wait to buy your dream car at the end of every month. This way if it was a bad month in sales the salesman will be more eager to give you a better price.Never show your excitement to a particular car even though that's the one you want. Snoop around the caryard a bit, look at other cars, even test drive em. That way the dealer won't know which one you really want. If you want a car and you know it's the one, play with him! not in that way but drag out long boring conversations as car dealers try to keep you there for at least an hour to tire you out and so you don't have time looking for all the other vehicles you were gonna look at on the day. Let them know your looking at 4 or 5 other cars on the day. Finally when you make him an offer, give them an offer that is 5,000 under what they want. Don't tell them negative things about the car they're trying to sell you that will just piss them off. It's just business m8 that's all. Last of all if you purchase a car and you pay the dealer and drive out of the car yard and those dealers or the salesman that sold you the car is smiling or happy then you just got ripped!!! big time, if he or she is pissed off or sad or down then you know you just ###### them hard!. Smart salesmen sometimes try to make you think you got a bargain. They're trained in this field and know what they're doing. Last of all ALWAYS make sure you get an independant review of the car, that means emissions check, lift that old girl up on a hoist get professionals to check it out not mechanic bob you m8 that tells you he knows everything there is to know about cars.
oh and I would never buy from a private seller mainly because most people change cars because there's something wrong with it, sometimes their reasons are legit like going overseas or don't need it because they just got a company car.
Many years of buying cars has got me good deals and bad ones to know whats a good deal and what's bad. Research is the key, 6 months of research on the car you want is a decent effort.
Good luck