LOW-BALL OFFER, Should I brother and what's my threshold?

[Benjamin Allen]

I've had my eye on a certain property for a few months now, I would have to raise a little rents that are current, but ultimately I should get around 45% cash on cash return. The assessed value is around 125,000 for a 4-plex. They are asking 114,0000. I want to put an offer in at 70,000. What should my back-out acceptance value be? I value this based on the numbers I've calculated and also being that the utilities are not separated. I'm think I might just hand them the total utility bills quarterly or monthly had have the tenants reimburse me after the fact, bad idea? I was wondering your thoughts biggerpockets! This is in line with my goal of getting close to cash-flowing one property at 1,000 per month. This would be around 800 per month and I will attempt to pick another one up later in 2016. I accomplished my firsts years goal in real-estate by cash-flowing 500 per month from my portfolio. 2016 is to have a total of 1,500 per month cash-flowing in 2 years.