i think reports of the bubble bursting are greatly exaggerated. MMRLE is definitely sucking up a fair amount of capital, and causing people to sell more games than normal due to needing room or cash or both in order to afford it, but i don't think it's more than a temporary correction. this effect is already well under way and i don't think prices have dropped much on most titles. INFLATION on the other hand has stopped. original MM seems the most affected so far - i don't think you would have seen a nice one for $8500 last year. everything else looks fairly similar to last year at this time, though.
pinball is still growing and hasn't yet reached its peak. when you see attendance at tournaments and events and expos level off (which has NOT happened yet) then you will see longterm price declines. but as of right now, pinball is on the rise, not on the decline.
i'm also not convinced MM dropping in value (as a direct result of the remake) is going to make other non-remade machines go down. i don't buy that MM is automatically the ceiling and all other games are priced as a function of its value. in my opinion, any decline in other machines' value right now is more attributable to the aforementioned capital and space issues associated with the remake, not MM's value decline.
just my opinion of course.