Do Solars Cost 2.8 GURPS Basic Set Dollars?

[Anaraxes]

(Likewise, for reference, the CrImp of CT and MT is roughly a 1977 US dollar.)

Roughly, indeed. Back in the day, I had worked it out to more like a dime. But it depends on what goods you choose as a benchmark -- especially since most of them don't exist! The TL15 1105 Imperial economy differs greatly from TL7 Earth, so it's hard to come up with one simple conversion factor.