2002 nissan sentra gxe for $2,000 -- good buy?

Honestly, I wouldn't touch it. The average annual millage is somewhere around 12,000 a year... That car shouldn't be close to 100,000 let alone 140,000. I am worries about the belts and engine life. Regardless, I could be wrong. Get the carfax and sit down with the owner and get a paper drawn that says if any mechanical failure occurs in i would say 4 months, they cover it, or you split it or something. I think it's risky