As a general rule, Priceof(Sol)=Priceof(Luna) + Priceof(PMG) + Priceof(HRM). Thus there is absolutely no reason to buy the Sol instead of the Luna unless you know you're going to be using both PMG and the HRM. But this is all retail pricing for new, original owner purchases. If you're buying used, the most important thing to realize is that the warranty is not transferrable; only the original purchaser is covered by the warranty. That is a very big deal.
