I was asked to do two helmets for the party. First I have never made a helmet and second how much should I charge for the cakes. Thanks in advance.
Pricing varies sooooo much over the country. I have no idea what is the 'going rate' in your area.
Since these will be 3-d/sculpted, I suggest nothing less than $3 per serving. The servings is determined by the cake sizes before carving.