Although there is a correlation between LLLL.com prices and LLL.com prices - the issue here is demand vs supply. As more and more industries find it neccessary / important to be online and be a part of this global community, it will drive prices for these rare domains through the roof.
Does regging the last LLLL.com drive the prices for LLL's? Not really. It will have a small impact, but it wont change the demand and it wont change the supply. I think the more LLL.com's become developed, the higher in value the remaining ones will go. If you study the market, and current sales trends, you'll notice that LLL.com's have been picking up quite a bit of steam lately.
Infact, you'll be hard pressed to find one for less than 4.5k
Justin