Per-deal fee or retainer on 20 doors? My spreadsheet won't settle.

The kill fee is the whole negotiation and you've buried it at the end. If they walk at inspection for a reason you couldn't have known, that's their risk. If they walk because their acquisitions guy changed his mind about the street, that's a $1,900 loss you funded on their behalf. Write two different numbers for those two cases and make them define, in the agreement, what counts as a diligence failure.

Naive question but the difference between $150k and $132k assumes 20 closings actually happens. Has this fund hit twenty acquisitions in a year before, in any market? Because if the honest expectation is twelve, structure B pays you $108,000 and structure A pays $90,000 and the comparison flips.

@vellum has it. Ask them for last year's closed count and their fallout rate at inspection. If they won't share it, price the retainer as though the answer is bad.

On working your own account: don't try to write a clever carve-out. Give them a written right of first look on everything inside the box within 24 hours of contract, and keep total freedom outside the box, and define the box tightly enough that both of you can tell which side a property is on. Vague box, endless argument. I lost a client over exactly that, over one house that was 200 feet outside the boundary we'd drawn on a map neither of us had saved.

Funds pay retainers all the time, they just call them something else. What they resist is paying for effort with no floor on output. So put the floor in yourself. Retainer with a minimum of, say, six qualified contracts presented per quarter, and if you miss it the retainer for that quarter converts to a credit against future closings. It reads as confidence and it costs you nothing if you perform.

$3,100 hard cost per closing with your own time uncosted is the number I'd worry about before I picked a structure. What's your time worth in that? If you're the closer on 31 contracts a year you're the constraint, and 20 acquisitions for one client means you can't take a second one, which is a concentration risk nobody in this thread has priced.

@parcel is right about concentration. One client at 100% of revenue means they set the terms next year, not you. I'd rather do 12 for them and 8 for someone else at slightly worse economics.

On the licensing question, the trigger in most states that have addressed it is compensation for procuring a property for another person, which is exactly what both of your structures describe. That's a state by state question and your attorney call is the right move, but ask specifically about whether a per-transaction fee and a monthly retainer are treated the same way where you operate, because they sometimes aren't.

Separately, if you do go retainer, get it paid monthly in advance. A fund that's slow paying a $6,000 invoice will be slow on the $3,000 ones too and you'll be funding their float out of your mail budget.