My instinct is to advise holding rents slightly under-market as your priority in this situation is to minimize vacancies so as to reduce your personal operating costs.

However, if your house hack reduced your housing costs from $1,200 to $600 per month, would that not be a win?

I signed the contract for buying the property as-is so I don't think the seller will pay for any of these so I am wondering if I should continue to proceed with this purchase.Paying an additional $18,000 will maintain a ~$420/mo cash flow but will reduce my cash on cash return to ~10%.

Once you stop the growth and expansion you reduce the inventory which cause prices to sky rocket.

Often times, the seller reduces the price to a fair market value after a few years and then the property sells.

What we didn't know is that the property did go under contract but for a reduced price $150K.

So your resident can accomplish the same thing you're shooting for at a much reduced price($500-$900, maybe, for 2 or 3 in-window ACs?)

Think rust belt to sun belt (a super cycle), think east/west coast high company costs looking to relocate to Dallas to reduce employee costs and be close to key strategic transportation routes (DFW, interstates) linking coast to coast in a few hours.The long term trend of more renters has a lot of legs left (millennials, boomers), cost of a house is going up as well as higher rates so that will continue to keep people renting as well.  

The investor negotiated with the county to reduce the code enforcement liens because he fixed the problem (pool). 

Your IRR then acts like all the other Calculations, but it's going to be easier to understand the results because it is entirely comprehensive.The Great thing about the IRR calculation is that if you are expecting ZERO cashflow, but you are expecting the Mortgage to be reduced, say a $1 Million mortgage reduced to $500k in 10 years, then that applies to the IRR since you need the Investment for the Purchase and the HYPOTHETICAL Sales Proceeds after the sale of the Investment.