The 1000 is a collector-only system. Great to look at; Not ideal for those who want to play the old games. The 1000 goes for between 25-150 USD depending on condition. A clean one with no yellowing and a working internal floppy complete with keyboard and correct mouse and good condition box fetches the most in an online auction.
Some acessories, like internal expansions or hard drives are really getting rare and could fetch more than the rest of the system.