OR should I base it on a percentage of equity earned that is predetermined before we close on the property?  

Meanwhile the average compensation is likely to further reduce from nearer 5-5.5% to 4-4.5%* These are personal hypothesis based only on twenty years and two days of the new rules. 95% of my transactions are buyer broker related, so you could say I'm biased but I an neutral.

Hence, why there is an up charge to make up for the difference. 

., after which I put my foot down hard and said “dark grey or light grey siding?”

I have negotiated a contract down to get it to be right in line based off of his super generic numbers that only be and his team deem a deal.

You may be able to find 15% down but even that is VERY hard to get and with the changing lending climate could completely dry up.

They owe 68k, it does need some work, I’m willing to put in the work to bring the value up if I can get it back on the gift, it should be worth about 200k, the house next door sold for 225k.How does gift of equity work?

They'll have resources.Also - check with your real estate broker regarding asking the seller for a credit (FHA allows seller credit up to 6% of loan amount) toward paying closing costs. 

We spent a total of just under 50k renovating the property, all new windows, interior including paint, flooring, updated plumbing, electrical, all completely renovated the interior including removal of popcorn ceilings, and all costmetic updates, cabinets, countertops, light fixtures.

Based on the raw numbers if your getting financing your looking at more than likely 20% down although 15% is available on an investment 4 unit for financing.