Got $100k business line of credit with 710 credit score to buy some more properties.Do you think it is better idea to buy a rental house (worth $70k) with the credit card paying all?

Market rents are $650 for a 1/1 and $1,200 for 3/2 in the area for this size house.   

Fellow house hacker here.

I was not interested at 1.2 mil but became motivated buyer when I could buy it for 800 and get 100k of upside I said sure why not..3.   3 houses  125k closing i put up all the money  he had two of them sold for 100k and that closed 5 days after we bought it so basis on the last house is about 25k .. and its on the market for 89k. 

I previously owned rental apartments and houses in downtown and have done fix-n-flips there as well.

With only 6 houses, I'm doing it myself.

With your price point I'd look for a duplex that is 350k or so, but if all you can do is a good house to start, then start there. 

A super ball number to get you going would be at least $190/SF-$220/sf ish... to figure out square footage it's probably best to connect with a Chicago architect like @Samuel Pavlovcik or @Prashanth Mahakali both can talk through the zoning and plan development process.

We were able to work with the sellers since they were going through tough times and wanted to get out of the house quickly.

Is this a unique form of house hacking, where the rental income from our owned properties covers the rent of our new rental home?