Re: DSLR Dilema.
Do not be bothered too much by price. Set your budged and buy a fresh piece. A second hand camera might have some glitches that you discover later and might bug you.
A DSLR is sort of a long term investment. 150,000 shots is nothing for DSLR. My roommate just snapped 7,000 wonderful pics on his 2 week trip to Australia using his old Nikon D40.
You have to be very comfortable with handling of the camera. If you shoot outdoors alot, your wrists might start hurting after a few hours of constant camera use.
Look for features you would frequently use, specially the sort of lens available for the camera. DO NOT think what camera would suit a beginner (unless you have lots of money to spare for experiments). The technology is not that complex and people learn quickly. If you go for an entry level camera, you might miss some features which you require 6 months down the lane. Photography is not about learning the technical details but about composition and people do that with basic cameras too.