We had a builder, that got greedy after we installed a large system. They wanted 20% of the work we did on future houses. I found out that they made other trades pad their estimates to the customer, so the additional markup the builder was demanding was hidden.

We no longer work for this builder. What a scumbag! And since he and his partner roll like this, their main supper started wanting additional money from the subs. What a sickening work culture to create.

Don't pay the PA! Any legitimate professional would have a disclosed management or finders fee. If someone is not willing to let their customers know they are getting paid for their services, then there must be a problem.