Avoid Over-Improving:Avoid making luxury upgrades that don't add significant rental value.

I'm trying to grow my portfolio, so my money is spent either on new properties, or upgrading existing one's. 

If you have the bandwith, adding bedrooms/bathrooms or a new HVAC can significantly increase ARV.First-timers often over-focus on minor cosmetic changes like new paint, luxury upgrades that aren't necessary for the area, and personal preferences that don't align with market trends.Let me know if you have further questions.Good luck!

The renovation will trigger upgrades to the systems. 

Wife and I spend over $30,000 to fix up and upgrade the house.

Holding on to it with painting of the interior and upgrades to countertops to be granite.

Find a good TLC project if possible something with good bones but may need some upgrades.

Or, you might want to sell some units and upgrade to higher end tenants. 

The house we purchased was an Air BnB previously, had many upgrades to it, and is in really good shape. 

  $1,800 if he doesn't need to bring anything up to code (or upgrade from downflow to upflow, etc.), and if it's straight out/in install sounds reasonable.