S.P.Q.R. is available in a limited form on line for free.
http://www.ancientworlds.net/aw/SPQR/GamePage
it does not have the wonderful music of the original full game.
The original game which needs some tweaking to run on XP is wonderful and a true work of art. Ditto re Rome: Caesar's Will, the trick to running that is to turn Acceration all the way off, then the sound will work fine. I got an original boxed set last year and it is a lovely game. It is expensive tho and hard to find so it is rare. One of the best of the Rome themed games. I saw someone listed The Amazon Queen as rare, it is available for free with the authors permisson on the ScummVM Site the full fully voiced version and it is a lot of fun. You will find a lot of other games that work great on ScummVM btw. As others have posted, i would consider a game "rare" if it is worthy of note AND not easy to find. Increasingly almost all CGI games will fit in this category so take care of your collections.
