Make the robusted donuts cost 2 utility credits

[Mouse]

After testing, I've found out they do heal pretty well. I don't think it'd be too bad to remove a red donut or whatever, but it's certainly no donk pocket or syndie pocket.

(healed me to 50% from 7% in one bite from pure brute)

Don't test them on just pure brute, I'm reasonably sure they have saline and they might have ephedrine as well.  I don't really want to join as secoff just to reagent scan a donut though so if someone who knows who to look through the code could tell us exactly what's in the robusted donuts (only the robust donuts are on the wiki) that would, I think, help in judging how much healing they can do.