Can you help me understand what would make this a great deal?

[Gabriel Hidalgo]

I was walking in a neighborhood in Napa, CA, yesterday, and I saw a house for sale with plastic on the roof. I called the realtor and found out that the owners have a tenant in the place currently who is leaving at the end of the month. Based on a contractor's proposal, the owners plan to sell the house and give the buyer credit to replace the roof as much as it costs. They seem to want to get out of it because why wouldn't they replace the roof themselves and get another tenant, right? I was wondering if this could be an opportunity to get a deal. Any feedback that you have would be appreciated. I am very new to this environment. Also, records show it was last sold in 2002.