As a prior contractor the fact he won't give you an itemized estimate is smart on his part and shows he's not desperate for your business.

If it’s a high end rental, I would consider it, but a smart thermostat would be a better investment IMO. 

Or a smart thermostat for your LTR duplex?

There so much more as well you can get into fix and flipping once you stack your cash ( or if your smart you'll learn how to use OPM "Other peoples money"  Grant Cardone on youtube teaches that pretty well.

A smart move would be to pay the extra money for the FHA install and then include heat in the rent.

Moen Flo Smart Water Monitor 3/4-in to 1-1/4-in Indoor/Outdoor Smart Water Leak Detector with Automatic Shut-off Valve in the Water Leak Detectors department at Lowes.comDoes anybody know any info on these?

I currently have 1 single family property that cash flows $1000 per month , the house could sell for around $500,000 and I owe $140,000 on it, it’s in a 15 yr mortgage @ 2.5 % (pretty good) - would it be smart to sell this home and use the equity towards the purchase of 3 similar priced homes?

The smart landlords also (privately) cheer this.2) Mom & pop landlords get out of the business and new development slows. 

You’re a woman, which means you’re smart, resourceful, resilient, strong, organized and efficient.

But you, you're smart!