Premiums for rare(er) T206 Backs

[Rhotchkiss]

Hi all. I am new to the forum, but very glad I found you all (indeed, I already screwed up and posted this mistakenly in the B/S/T section - sorry!).

I am a longtime collector - have assembled and sold a few collections - and got back in the game early last year. Lately I have focused on the T206 set, and particularly rarer backs of HOFs. In addition to a Magie 3 (Piedmont), I have acquired a Cy Young bare hand 7, sovereign back; a Cobb red SGC 80, Tolstoi back; an Evers Chicago on shirt BVG 5, broad leaf back, a Lajoie portrait 5, Sovereign, and a Walter Johnson hands at chest 5, Old Mill.

I really like the rare(er) backs but would appreciate thoughts on what premium they worth (over Piedmont and Sweet Corporal). I understand that some backs are rarer than others, and I don't need the minutia of the factory (although series is relevant), but just wondering what you all thought the premium one should pay for the various HOF rarer backs. And further, what extra premium, if any, should be given a relatively low population or the highest graded of an example (like my Cobb Tolstoi)? Sincere thanks