Profit is also a far more valuable metric than cashflow if you can do the extra legwork.Things you need to add back to cashflow to get to profit:- Principal payments on debt. 

At the time, we thought, "Why spend the extra $100-200 if we do not have to?"

Seems "extra" to me but I'm not a loan officer or underwriter. 

You also want to make sure if you've included water and electricity based on one person living there, you account for the extra consumption-if the tenants pay water and electricity, this won't matter.

To prepare I am saving some money for the down payment (plus extra in case of any issues or necessary rehab), and building my credit as much as possible because I am only 21 and started my credit history only 5 months ago.

@Kevin Hoff If you do replace, spend the extra $200 or so and get one with windows.

That means you can cash out all $75K that you invested leaving $0 in the deal.Answer to the last question would be three numbers: ARV, Purchase Price and Rehab Cost (ignoring extra cost which can add up quickly if you are not buying with cash)

I found the contract here on BP to be pretty good, but here in VA, I need a couple of extra documents to make it complete.

If you do, everything is there besides extra property information and city list.

Some potential problems in my opinion:- 2 tenants on the lease which complicates the agreement- May have overnight guests whom I would not want to stay- May sub-lease the extra bedroom to people who I do not approve of- If only one moves out, I cannot rent the whole house to a family.