Potentially taking losses while student house is vacant

[Aidan Birmingham]

I am negotiating a seller financing deal for a student house at $380000. The problem is that the house is vacant for the first time is years because it wasn’t listed properly by the owner that inherited it. Since the leasing season for students passed there is a good chance it will be vacant until next June. Once it is rented the property will cash flow about $1600 a month which would be about 30% cash on cash return. While it is vacant I will be losing about $2800 a month. I attempted to ask to defer payments until it is rented but the seller will only offer interest only payment at 7%. Do you think I should move forward given the returns once it is rented or is the short term loses too much?