Pay buyer $15K for closing cost or look for another buyer ASAP???

[Abiy Tedla]

I'm selling my house-hack ready rental townhouse in the hot RE market in Norther Virginia.  Before my realtor listed it on the market, I presented to the tenants a letter of intent to sell my property to give them a heads up (top 2 levels and private basement apt rented to 2 diff tenants).  Additionally, I presented them with the option to buy the townhouse if they were interested at a fair market price.  One of the long term tenants renting the top level was interested after I let him know that he would be essentially paying close to the same amount if he kept renting the basement to the current tenant.  He reached out to an agent who presented us with a contract offer agreeing to the price but adding a contingency for me to cover the entire $15K closing cost.  I was caught off guard about the tenant adding an agent to the deal. The agent hasn't done anything other than probably convince him to pass the closing cost to the buyer and draw up the offer letter.  Furthermore, it adds to the overall cost of the sale.  I was equally surprised about my tenant asking me to cover the closing cost in the current housing market.  My initial thought is to go forward with the listing and selling of the property at the market price without paying the closing cost.  I'm planning to do a 1031 Exchange so I want to make sure that I can maximize the profit in order to get the best deals.  I've been very fair to my tenant who hasn't seen a rent increase for the past 5 years and the market price is fair as is (fully renovated townhouses are selling for $25K more in the neighborhood).  I also offered to replace an older major kitchen appliance and fix any remaining minor issues.   Should I keep negotiating or go ahead with the listing and selling of my townhouse?  I don't suspect that it will take long to find a buyer but time is of the essence in business...My realtor gave me some ideas but I would like get some input from the BP community on this tricky situation.  What would you do???  Thanks in advance...