mazdarx7

i hope you all can help me out..i want to buy a 240sx the 1989-1994 models.. and i would like to know which year is the best to buy? what problems will i encounter? what is the least i could pay for a good condition 240 with low miles? at what point in mileage does the car start giving problems? and what things should i check in the car when buying? well thanks i hope you guys could help me out.