Having read Visions of Peace, I have to say, it shows.
JMS's history suggests he's generally happy to keep Babylon 5 moving (as for example, the graphic novel he's writing to finally complete the Crusade story), but he doesn't think it's wrong to receive payment for his work. He's defended members of the B5 cast who refused to do interviews for the DVDs on the grounds they weren't getting paid for it.
I don't have figures, I've only just heard about JMS's comments myself, so I won't defend blindly, but if he's going to be working on something, he deserves the credit for it.