Sold my overflow leads to two guys who now want a login

Run your own numbers before the build question. $2,400 over 31 form fills is $77 per fill, $266 per real conversation, and one contract per month at that spend. Your $250 lead price is below your cost per conversation, so the resale is only working because the buyer takes leads you already paid to qualify and you would otherwise throw away. That's fine as scrap value. It's not a business yet.

The flat monthly fee changes the risk. Per lead, you get paid when there's something to hand over. Flat fee, you owe volume every month whether the ads cooperate or not, and your form fill count has no floor. Two buyers on a subscription means one bad month of ad costs and you're refunding or apologizing.

What the answer depends on: whether your cost per fill holds as you spend more. Search volume for that intent in one metro is finite, and most people find the second $2,400 buys fewer fills than the first. If it does hold, a portal starts making sense because you can add buyers without adding your own hours. If it doesn't, you have a lead reselling side effect and a portal is a distraction.

Cheapest next step is neither option you listed. Raise your price on the next three leads and see if both buyers still take them. That tells you whether you have pricing power, which is the thing a subscription actually rests on.

One more thing: getting paid for connecting sellers to buyers can touch brokerage licensing rules, and those differ by state, so run your arrangement past an attorney licensed where you operate.

I'm in the middle of the licensing coursework right now and the compensated-for-finding-a-buyer question came up in almost every module. It isn't clear cut and it's state specific. Doesn't mean you can't do it, just means get it looked at before you're collecting monthly money from two people.

The portal isn't the hard part, honestly. I built something similar for my own team and the plumbing took a weekend. The hard part is the second month, when a lead shows up in the portal, both buyers see it, one calls the seller and burns them, and now you get the complaint call. Decide the routing rule first. First look for 24 hours, then it opens up, something like that. Write it down before you write any code, otherwise you're arbitrating fights forever.

Question that might be dumb: are you telling the seller their information goes to other investors? I'd want that sorted before scaling it, because the day one of them complains you want to be able to point at your own form language.

$250 for something you were going to delete feels low to me. Guys on my side of the business charge for a referral and think nothing of it. Try $400 like you said and see what happens, that's a five minute experiment and the portal is a month.