Lipsey's is a Distributor.
As far as any significance of a "Lipsey's Special" there can often be a little premium in the secondary market due to the variation of a factory cataloged model.
Distributors can get Ruger to build a gun with a few features not offered by a regular production model. Often in lower numbers,, (500-2000) to get Ruger to build it. They guarantee to Ruger they will purchase all of them, so Ruger has guaranteed sales. And often the features they get done are desirable to enough people that the sales demands exceed the projection. So, sometimes they can bring a premium. And often,, the fact that a distributor got that particular model built,, it's a way to describe WHAT it is to other folks.
And as noted above,, Lipsey's has done a LOT of various guns that many of us want,, so they have a very good, close relationship with Ruger to get stuff built.