Where is all the new stuff that we had delivered to install?  

if you're willing to put up with the pain and inconvenience - moving every 1-3 years, living in the smaller / worse units, DIYing things - you could have a portfolio of 5-20 units in 10 years, just by using your house payment.maybe the house you have would be an OK rental. 

The first tenants are moving in July 1, and they have asked me to cover the costs associated with the installation of any new services (i.e., internet), and then they will transfer it into their name at the start of the lease.

When was the system installed or the well drilled?

I know that I've already go about 50k in equity in the property but the last appraisal was before 18 new windows @ 20k were installed.

All I had to do was disconnect the icemaker line and install the shut off valve onto the existing line so that the Home Depot delivery crew could install the fridge seamlessly. 

This may be an overly ambitious strategy considering that I am inexperienced in both DIY and sales contracts, but in theory it seems like a very efficient option.

We installed one in our STR and it’s been great! 

If you have natural gas to that spot for a tanked unit, swapping to a tankless is cake.Insulate the garage door if that isn't done.If you are local and handy, you can do a DIY mini split in there for under $1000.

I had a mother of a college student call complaining because we told her the house was cable ready (meaning there were cable lines already installed-and trust me, we explained to the daughter what utilities were included in the price and what wasn't) and she was very distraught when she connected the line to her tv and got static.