Answer:
Selling price of the house.
Step-by-step explanation:
I don't know too much about housing, so here are my sources.
"Typically, home buyers will pay between about 2 to 5 percent of the purchase price of their home in closing fees. So, if your home cost $150,000, you might pay between $3,000 and $7,500 in closing costs. On average, buyers pay roughly $3,700 in closing fees, according to a recent survey."
Quote from: https://www.zillow.com/mortgage-learning/closing-costs/
https://www.bankofamerica.com/mortgage/closing-costs-calculator/
Hopefully this helps.