Commemorative Russian Gold Medal ID And Value?

I have several gold russian medals and have been researching (US and Russian) websites but I can't really find very much info on them. Can you help ID and provide a value for these? or at least a reference site I can go to that actually has these coins. I have searched numerous coin, medal, token russian and US sites.
I believe they are commemoratives. I am having problems posting pics, so I will tell you what they look like
1) front: f.shalyapin (profile) back: Boris Godunov (holding his hand to his head)
2. front: Dostoyevski(head turned slightly) back: Desktop with books, feather ink pen and branches around the periphery
3)andre Rublev (head turned slightly, 2 fingers extended, standing next to a piece of wood)back: Angel with halo holding a staff while in a sitting position. This medal I found 1 auction for in russia going for about $2000 US
4) Front: repin (head turned slightly) back: 3 boatman on the vogle (a painting)
5. Front: Rachmaninov (profile) back:1873-1943 piano keys and branches along the periphery
6. Front: Puskin profile back: a lyre with a ribbon on each side, scroll with russian writhing, branches on the periphery. I have found many medals that have the same front (the profile) but the back is not the same, and all of them are bronze.

I would appreciate any feedback. I have identified the persons/professions on each medal, but beyond that, I am stuck. These have no denomination on them. Please help!
GB