Since is all digital, charge per pic they want to buy. If you took film it would be per pic taken.

How many pics did you take for the wedding?

Im an AH, so if I where a photographer, Ild make the client browse through all of the pics and choose the ones they wanted and charge them acordingly.

Film would be for every pic taken, digi would be for every pic they bought.

I dont know what the overhead is so I cant give advice on what to charge.

Find out what other pro photographers are charging in your area and go from there.