Move on and count your losses, and find another contractor with a signed contract before work or money swap sans.

If it goes into your exchange account then at some point before you are ready to complete your purchase you will need to swap it out with cash from the outside - could be any source it doesn't matter. 

Tell them each new tenant generates additional work on your part, therefore you will charge them $XXX every time there is a swap.

Every six months the come in, test the detectors, and swap out/recharge the extinguishers.

Maybe swap the labor experience you have with someone who is in the investing world that could teach you the ropes. 

I will essentially swap back and forth between BRRRR and development depending on the market to continue build my business.   

For those insisting on only new I would also suggest keeping used ones on hand as a quick swap out when appliances fail so that the tenant is not without while waiting for a new replacement. 

I may want to swap out kitchens/baths/etc before selling to get a better top dollar but I am not there and they are just my cash cows.The nicer, complete houses I have noticed prices pushing to the highest they have been in the last 7-8 years. 

I've done deals with livestock, machinery, cars, boats, an airplane, timeshares, vacation packages, labor traded, professional services, swapped RE, took jewelry as collateral, about everything but the first born, all of it was simply using other assets to leverage a deal or trade in lieu of money.

They'll be the ones to tell you how to swing by your rental and do stuff: check filters and patch drywall holes, everything from mowing grass to clearing drain lines, no job is too small—not even swapping batteries or cleaning house.