@Gadolhadorah
” Most good contract and transactional lawyer charge at least $500-$700 hour so that should be a good starting point.”
No they don’t. That would be very good or exceptional transactional lawyers.
The type of contract for a simple sale and then buyback would be spit out of software by a paralegal or legal secretary billed at $200 per hour or less.
The Rav is not negotiating for you when he comes to pre-Pesach terms with the non-Jew. He is negotiating for himself and all others whose chometz will be included in the sale.
Many rabbeim don’t actually do any of this, but simply act as a sub-agent for another who makes the sale.
That said, in our shul the amount given to the Rav varies between $18 and $180. This is a holdover from the days when shul rabbis had to supplement their meager salaries with this kind of income (also matzo sales, lulav/esrog, Bar Mitzvah lessons). Today, we pay respectable salaries (100K plus in our area plus house, car and perks) and don’t nickel and dime the congregants.