However, sellers should take note: while prices are up, the percentage of the original list price received has remained at 97%.

Instead, they typically provide cash for a percentage of your home's value (usually up to 30%) in exchange for a share of future house price appreciation.

If the policy limit you have selected does not meet the specified percentage, your claim payment will be reduced in proportion to the deficiency.

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

This list uses an average yield percentage formula to elect the winners.

Reinvestment/Expansion (10-20% of Income)Rule of Thumb: Allocate 10-20% of your income towards reinvestment in your business or properties.Why: This fund can be used for purchasing new properties, business expansion, or other growth opportunities, ensuring continued business development.Summary Breakdown:Mortgage Payments: 25-30%Operating Expenses: 30-35%Emergency Fund: 5-10%Capital Expenditures: 10-15%Paying Yourself: 10-15%Reinvestment/Expansion: 10-20%Adjust these percentages based on your specific circumstances, risk tolerance, and business goals.

This has yet to be discussed in detail, but it would be a percentage of the monthly rent. 

If Michael wants to keep the house, he buys out Jacob based on Jacob's cash contribution to the purchase plus/minus some percentage of the appreciation/depreciation since purchase (% could be based on their respective cash contributions to the purchase).

Would love to know percentage of sales across america where the sellers agent negotiated a listing for say 1%, 2%, and so on.

In such contracts it is specified what they charge per hour or a percentage of the rental income.