Hm... The total before shipping, excluding VAT, was 668€. The other pair of RTW taller shell boots (not on the e-store) I purchased last winter was 483€. So maybe the MTO markup is actually... 38%? Unless the cost of that boot has increased, which it very well may have, since the shell chukka on their e-store is only ~456€ excluding VAT, and uses significantly less material.
Okay, this is what I think: base model would be ~320€ excluding VAT. +194€ for shell (or 60% extra, but I don't know if it's actually a % upcharge), so 514€. Then +30% MTO upcharge on top of that.