altair 8800

Dumb question, but what might an Altair 8800 be worth these days? A friend is getting one from his father, who got it around the end of 1975. He asked me about sources for manuals and documentation, plus sources for boards to upgrade the system. Further questioning revealed that he wont get the unit until he travels back to visit the parents, and that the unit apparently has a 256 byte memory. This small scrap of information leads me to think this could be an original kit built system, with the original memory and probably hasnt been upgraded. If so, it could be a very dumb thing if someone who is clueless decided to upgrade this system, when he may actually have quite the collectors item in original condition on his hands... I'll pass along any information, or sources of documentation or scanned in manuals, that anyone can provide. -Lawrence LeMay lemay(a)cs.umn.edu