Found a deal... now how to make an offer?

[Rebekah Keller]

HI BP!

So, I finally found a deal that I want to make an offer on. 
It is a 4 unit... 2 need some light rehab... 2 are ok ( I think they have tenants but haven't been in them)
It also has a few years of  back taxes....

I asked if they would go lower... he said no, but he is not the decision maker.  
It was recently reduced $44,000 in asking price... that's how it got on my radar.

My question is... I want to offer on it...but I need a way to back out of it... if something is horribly wrong with those other 2 units, or something unforseeable. I am a newbie and just nervous... but ready.

Please help... what is my next step? also.. if anyone wants to look over this deal for me...  :-)