Are you sure the landlord collected May rent or maybe used one months free rent as an enticement to rent the property?

Start with BiggerPockets Ultimate Beginners Guide (free).

They want instant gratification.It's a cold world though, you ain't getting that without a cost.

Just to give you an example of the type of thing you'd be potentially looking out for, if the community has a pool terrace planned and it's orientation in the new building would face directly towards your property, that could be a source of significant noise and disturbance for you/your tenants, and could make it much harder to sell your property once the new building is built and occupied.On the positive side, new apartment buildings cost millions of dollars to develop and build, and developers really only sink that much money into areas where they're forecasting rent growth and property appreciation for their investment.  

Excel can easily do all this.You can likely download a free template that already has all the formulas you need.

My recommendation would be to own residential first so you have a much better understanding of the costs to own real estate.

My thoughts from the little I know about the raw numbers however:1) You have no reason to not raise the rent at least a small amount to compensate for the extra cost of ownership the past few years.

I've encouraged them to contact a 1031 specialist, but this question has me curious so I wanted to bring it to this forum for consultation as well.

Costs the same to put on a new roof. 

It sounds like you'll have well over $100K into it, between down payment and closing costs - is that accurate?