Scotz,
I too have loads of RM FDC's. They are beautiful but sadly worthless.
I cannot sell them, no one wants them. I have some coin covers too that RM are still selling at £15-£18 a throw. You cannot get rid of them for $6 !

.
I stopped after a while when I began to learn a bit. But it cost me. However, I am not in it for the money and some covers are beautiful...the definitives especially.
But the stamps are all CTO's so soaking them for a used collection is not an option.
Oh well.
Londonbus1