Renegotiate or walk away?

[Eric Dymesich]

I'm in contract on a Duplex and the closing is Monday. Its friday and me realtor just called and said the seller can't close because there is a tenant in one unit that won't leave. (The tenant is also behind on rent.) I required that the unit be empty before closing because it needs work and the renters were behing on rent. So I have a few options. 1-Back out of the deal and start looking for a new deal. 2- Change the closing date. 3- Or make a creative counter offer. Maybe like $ off the price for every 30days the closing is delayed or some other creative idea. Let me know because this is my first purchase so I dont have experience to fall back on. Thanks!