There are a lot of competitive collectors that prize scarcity. Some people have highly limited space (be it for legitimate lack of space or an unruly spouse) and can only have a few machines . . . so they think why not go all out.

For games like BBB, you just don't see them come on the market very often. People can ask for them what they wish. MM is a game that was under produced right out of the gate and it was such a monster earner on rout the operators didn't want to sell them - so they slowly defused into the home use market.

Another thing to note, and since you mentioned STTNG, I think a couple other items often come into play for the games that have been out a long time . . . how reliable are they? STTNG does not have the same level of reliability as AFM, SS, MM, TOTAN, etc.

I believe that if you are not particularly skilled at constant tweaking then you should avoid the high maintenance games like STTNG and go for the more reliable games. I think many people feel this way and this is why STTNG perceived value/price does not compare favorably to the fun factor (the game is a blast yet many, like me, shy away from it because of at least perceived maintenance issues...TZ is another game like this).