If you are financing a property, most lenders will require the builders referral fee to be used either for closing costs only (the only example of an allowed direct payment to you) or paid to your Broker of Record. If you're the Broker, and financing the home, the referral fee is not always eligible to be paid to you.
The path of least resistance is often to bring a Realtor with you like USCTrojanCPA, IrvineRealtor, or others who have 1st hand knowledge of each builders processes and procedures. Yes, it might mean a lower net to you, but that IMHO is the price of convenience and experience. I know the wheel has been invented, so why should I go through the trouble to re-invent one?
My .02c
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