NEED HELP: I want to get creative with Seller Financing for some commercial lots.

I have some lots for sell in Cedartown, GA. They are zoned commercial and altogether they are a bit under 2 acres of land. There are 6 lots of mostly cleared land in the front and 1 bigger lot in the back. The lot in the back is considered to be in a 'flood way' but can still be cleared and used for something. There's a small creek that runs near it.

Earlier this year I was offered 110K out right. However, since the one lot that is in a floodway was going to cause issues when it came to building, it slowed down the process. The buyer offered to put up a down payment but wanted 120 days of due diligence to try to remove the zoning issue with the back lot. I said I could accommodate if the down payment were non refundable. It seemed like it was a go, and I knew through contacts that they were at the city inquiring already. I assumed he was just trying to get all his ducks in a row and stretch out signing anything before having to do a non refundable payment. I let it slide. However he then went ghost for several months.

He has now came back, after doing his homework I'm sure, and says that he can't do anything with the back lot since it's in a floodway and that the city will not allow him to build town homes like he wanted but has ideas for building something commercial. But since he can only do parking space on the back lot, he can no longer buy out right since that back lot is pretty much useless to him now. He asked if I'd do seller financing and that the city says it would take about 5 to 6 months to give him the necessary permits to start building. I said yes, although I've never done it before but this is where it got interesting.

I was thinking of getting 20k up front and adding some sort of annual interest to then get me maybe a total of 120k-150k in a span of 5 years. Before I could tell him this, he offered 20k up front and another 40k in 6 months once he knows he can get the permits... and that's it. Half of what we initially spoke about! I told him NO, but even though he insisted on the back lot being useless, I could tell there is still some interest.

Any who, even if not for him, I'd like to see what help or options I could get in getting creative with this seller financing. I know there's some creative ideas out there to have people show more interest. Like I said, I've never had to finance anything myself so I'm not sure if there's a set way to do this or if there's different ways to go about it. Can I ask for a non refundable deposit and then give him time build, once he knows there's the possibility of money coming back then charge more after a certain amount of time for not paying up front?

Any help or ideas are greatly appreciated! There's a link attached to the tax assessor's page showing the 7 lots. The one that's completely detached from the rest is not for sale!

https://qpublic.schneidercorp.com/Application.aspx?AppID=690...