Since the calculated prices on a variation (+ - etc) definitely don't work, I changed over to a fixed price. But still the first 2 variations added calculate the price correctly, the third doesn't.
Opt1 Opt2 Opt3 Result
10.00 0.00 5.00 10.00
10.00 5.00 5.00 15.00
I've deleted all variations, and readded them one by one to isolate the issue.
What's the best practice for this or is it not possible?
And is the "price" field in the parent variation set used for anything or should it be left blank?