Here is what I think Stern has realized.
All of the other pinball companies and I mean ALL OF THEM have raised their base model game into the 7000 range. Willy Wonka SE is 7500, Spooky is 7, American Pinball I think is 7200, and the list goes on. Who knows what Chicago Gaming is going to do with their next standard versions.
I also think the ICONIC themes are more or less gone. I doubt very seriously Stern will have another 5k plus pinball game unless somehow they can snag LZ, Harry Potter, or something that so far no one can get.
Sell fewer machines, but make more for each one you sell. They're in business to make money, and if you'll pay it they'll take it.
When you stop buying you'll see the prices drop I would imagine.
People on pinside need to understand that just because a new game comes out doesn't mean you need to buy it. You buy it 4 months later you're bored of it you want to sell you lose $1500. Patience is a virtue just wait for someone to sell theirs.
Look at Munster LE's they're down up to $3000, patience would have been a real benefit on that machine.