IMPACT fees, and other building fees - What do you pay?

[Karen Margrave]

I'm curious in different parts of the country what builders and remodelers are paying in fees. I have a property in CA. It consists of a 4600 sq. ft. house and shop/game room building that I am converting to an ADU. However; when the Shop building was originally built it was permitted with a bathroom, and has utilities, so there's is absolutely no new impact on any County services. But, the property being in CA, and every County being in desperate financial straits, they are charging me $8400 in impact fees, plus $3000 for plan check (the only thing being changed is adding a wall to get the living space down to 1200 sq. ft.) In your areas, what are some of the fees charged?