@randahl
Polling places should have a stack of prefilled ballots for photo ops, one with an X at each party (ideally each person), with a large "invalid" stamp on the parts of the ballot that you are not taking a picture of.
Bonus points if they are filled in manually at the polling place, so the X will be different.
That would make it hard enough to prove anything that offering to pay for photos would be useless.
./~