Price is a function that has an initial value of 200 (200,000$) and it increases the Total Buyer is less than Buyer by 0.5, and decreases when the Total Buyer is greater than Buyer. 

Buyer is a function that has an initial value of 50, and it increases when price is less that the average by 0.5, and decreases by 0.5 when price is greater than the average price. 

The initial buyer increase rate and decrease rate is 0.3

The stimulation when its in initial form shows that buyer rate increases and decreases over time, while price also change over time, slightly. The relationship between the two can vary upon external factors such as the location of the property, how many people are willing to sell their property, financial state etc.