Hmmm well in public a Rurouni Kenshin OP Saitou 
cel for around 5K USD. I don't know if it got 
sold however, maybe because it disappeared. 

Privately I've been offered 3 Saitou cels for 
around 10K a long time ago. I didn't buy it not 
because I thought they were ridiculously priced, 
I just didn't have the money for a one time 
purchase. Oh but those pan cels were indeed 
worth it... I collect RK and specifically Saitou 
so I think I have a good idea of what they're 
worth. At least I tell myself that. LOL.