I am a bit surprised there isn't currently an 11 -> 13 upgrade.

I didn't upgrade to 12 for two very good reasons, and one of them was the negative outpouring over problems with 12. Very likely, there are others like me. They saw all the hate that 12 was getting (and secondarily, a lack of new relevant features) and figured they'd just wait until 13. I considered upgrading to 12 not all that long ago because I saw more and more posts saying problems were being fixed.

If it were me, I'd do the following:

Poser 12 - 13 upgrade = X.

Poser 11 - 13 upgrade = X + (X * 50%)

Result then, Poser 12-13 'rounded' = $99, Poser 11-13 = $149.  If that were the case, Id have already upgraded.

Best regards,

chikako
Meshbox Design | 3D Models You Want