FLR financial sources

Hi
I cannot seem to find an answer to my question anywhere,can anyone help, i am preparing my wife application for FLR. and working out my income. i understand now that proceeds from the sale of property can be used as income. in my case I am selling a property via rent to buy so the buyer pays a deposit and then pays monthly over the next three years followed by a final payment. does the monthly payments count as income for the purpose of the UK visa