One other thing to consider is tax implications if you sell. 

Stupidity tax. 

I also want to make sure tax wise I have the best structure possible. 

Hi Jacob - I have a network of partners from financing to tax strategy, REI coaching, etc...who can help answer a lot of these questions and get you some guidance. 

After subtracting all that from the 3333.00 , whats left is what you can spend on a mortgage payment including property tax, home insurance and mortgage insurance.

Bare minimum for me is $20,000 after a flip (before IRS taxes). 

a single family to a multifamily property is perfectly fine.Lastly to your question - You must purchase at least as much replacement investment real esate as you sold if you want to defer all tax.  

@Josh Roman I have one that’s two houses with three units on one tax parcel linked to a second tax parcel that has always been on one mortgage.

Same school district, property taxes etc.

I think most of his flips are in inexpensive cities like Cleveland, Detroit area, etc. https://flipsystem.com/faq/I think $10,000 to $20,000 (before IRS taxes) is a really small profit margin.