Ultima II (Apple II), Ebay Auction.

Very scarce to find nowadays on Ebay, here's a copy of Ultima II.

It seems to be in very good conditions but the seller doesn't say if the game itself is working or not. This is definitely a key point when you approach a piece like that one and it can massively modify the price rating of the game.

However we should consider that working games, especially from early eighties, will be more rare due to the natural deterioration of supports. A common problem that unfortunately we will all have in at least 10 years.

Edit: Auction ended at US $338.33 (circa €271)