Ok I'm new here (only downloaded the pdf yesterday) so apologies if this has already been addressed somewhere, but;
Looking at belts and headbands (p.140-141), the belts which increase physical ability scores are priced as follows;
Bonus...Any 1....Any 2....All 3
+2........4000...10000...16000
+4......16000...40000...64000
+6......36000...90000..144000
So far, so good, but when we look at the headbands which increase mental abilty scores we find;
Bonus...Any 1....Any 2....All 3
+2........4000....5000....16000
+4......16000...10000...64000
+6......36000...45000..144000
Presumably this is just a random error? Or is there some reason the Headband of Mental Prowess (any 2) costs half price when the "any 1" and "all 3" versions cost the same?