We are in the process of analyzing properties and are eager to get the ball rolling.

Throw the ball in his court 

Now if you go over 4 units its a different ball game. 

For what it's worth, these tenants have been super on-the-ball up to now about everything and I did a deep due diligence check and got nothing but rave character reviews and financial history.

Ouch.. but we still made a bunch on it.. but those things happen.In one subdivision I was building in the neighboring builder went with the cheapo framer.. and when you went in the house it look like the TREES of MYSTERY house along the Northern CA coast.. yup built it out of plumb drop a golf ball at the back of the house and it will roll right out the front door on its own  LOL.. not sure how much he lost as he sold it as is.. but no one in there right mind would pay close to retail for that.

. - I'm sure it's doable but the numbers have to be very precise. 

Both units also need brand new septic systems, which the seller will replace.My question is...should I wait the few months for the seller to take care of all of these issues and make sure that it is done right before I purchase, or should I offer him a low-ball cash offer to walk away and then get a HELOC on the property to purchase my next investment.

I am in the process of making an offer so just want to get a ball-park number even higher price it will be ok, so I can make a conservative estimation, because this property may go fast.

It's a sensible term in that context because construction is often precise, an art even, and hacking is something you do with an axe. 

It's also a good time to get the ball rolling, test the waters on finding a better tenant(s).