I've been in the hobby for 18 years and I think a few things have happened.

1. There are no longer a bunch of games coming off route. It used to buy you could buy a route beaten TAF for a decent price. Those have all been scooped up and restored, so there's really not a lot of players condition games out there. And anything restored will have a hefty price tag on it.

2. The internet. Yeah the internet was around in 2003, but it wasn't a daily part of everyone's life and other than an obscure newsgroup (RGP) there wasn't much to go on in terms of pricing. Nowadays sellers can easily find pricing.

3. New pin price. As mentioned above, new pin prices are in the $5500 - $9000 range. Not that long ago, new Sterns were 4k which creating an artificial ceiling for all but the most sought after B/W pins. With the higher NIB prices, that ceiling has been raised.

There have always been flippers out there, so I wouldn't point to that as too big of a driver.

Bob