Heya, folks.

I've got four of the old AD&D gamebooks--Lords of Doom, Trail Sinister, Sceptre of Power, and the Sorceror's Crown.  All have the character cards still intact and attached.  All have some interior cover yellowing; Sceptre of Power has discoloration on the page edges; Trail Sinister has the upper back cover corner missing.  (I'd say maybe 3% of the cover total.)

Anyone know what these are worth?  Prices seem to vary wildly online.