It's bordered on 3 sides by SF communities that are selling out quickly.

@Luis Garcia Time is not on your side so act very quickly. 

Search the forums to get a better idea of calculations to do a quick look and more thorough investigation if you like what you see. 

Let them know if they are willing to sell, you could pay them cash and close quickly.

The BRRRR strategy is very appealing; I'm looking to expand quickly and do exclusively buy-and-hold.  

Often in partnerships you may have different agendas like one wanting a quick profit and the other wanting the tax advantages of a long term buy and hold.

In retrospect that was a terrible financial decision, but oh, well.My next job was across town from my house which was a reasonable commute a long time ago, but quickly traffic became too much, and I decided I needed a closer place.

Co-signer or not, if they don't have a job and can't get one quickly, the rent can't / won't be paid.Still may be a good idea to get a co-signer, but I'd put primary focus on employment history and bill paying habits as seen on credit report from when they were fully employed.

It's so culturally diverse and rich community.  

Other reasons they may be motivated are that they own the property but don't live there and just want to get rid of it for various reasons (called an absentee owner) or they inherited the property and just want to sell quick but they don't want to fix anything up first