2-4 years for a male. 10-12 years for a female. Of course if you feed them more and keep the temps up they will mature faster and ultimately die sooner. Sac production may also effect the life span of a female.
Depends on the size of your spider, how warm/cold you keep it, and how often you feed it. Generally speaking, males have shorter lifespans than females, as they live about a year or so after their maturing molt.
I have three. Two males and a female, all of which I got as 2nd instar in April 2009. The males are about 3.5", as I feed them every two or three weeks. They are a molt behind my female. She is 4.5, and I feed her every week.