Charging for render nodes

I’m not sure I follow your numbers.
Upgrade price from 1.5 to 2.0 = $550
Maximum Upgrade price from 2.0 to 3.0 (with 11 render nodes) = $980
(980/550) * 100 = 178.18%

I’m no math wiz, am I missing something? If you need more than 11 render nodes per user, then I would suggest you contact Vray sales personally. They have mentioned several times that they will be willing to work with you if you have large demands.

Regards,
Andrew