What KTM, help!

Hello everybody, I’m excited about you because I think you’re really aware of what you’re writing. So I’m asking you to help me and that’s: I want to buy a KTM SM and I have three to choose from I’ll just introduce you all three times: The first would be a KTM 640 LC4 SM BJ. 02.2002, Km 7600, 2nd hand, check book maintained, color: red/black and the price would be 4590.- However, both tyres would need 2 new ones at the end. The second would be a KTM 640 LC4 Prestige SM, BJ. 20 03, Km 8000, 1st hand, checkbook maintained, according to the dealer the previous owner was dropped once but I did not see any traces of a sturtz and the dealer said that the fork etc. was all in order and the price was 4990.- Tires are OK. The third would be a KTM 660 LC4 SM BJ. 2004, Km 1800, 1st hand, checkbook maintained, of which I know nothing at all and with the 660 I have never fasted, the crusher is dark blue colored ubd although almost until the end silencer no indication if that has something to mean, small scratcher and the price would be 5500.- All three are from the dealer and very well maintained and also on all would be buy off a 12 month warranty on it. What do you think you should buy if you want to have a bike to go to work and have fun. How long do the motors of the KTMs are the prices good or overpriced? Please give me a advice so that the purchase is easier for me. I thank you in advance for your opinions Greeting James0179