CGC 9.8 is worth around $350-$400. If you sent it to Rich, then I guess you are looking for a Totleben signature, which pushes the price well over $500 (if it stays at 9.8 s/s). If you went for a sketch, and you got a good one, these have sold for around $1,100, if they held their grade (9.8 s/s & sketch). However, the Totleben prices will come down a little as he has now completed two private signings and will be attending Cincinnati as well this year.
As for a #15 CGC 9.9, well it is unique and sits at the top of the census so Ewan's estimate of $2,000 seems about right and his #12 9.9 should make over $500. I might have to sell one of my kidneys.......