They also usually are more energy efficient as the water is heated as needed and not heated to store in a tank that might not be used for many hours and tanked heaters typically have heated more water than needed (and this is desired because running out of hot water is a bummer).I do not want an annual maintenance effort as large as descaling a tankless water heater at my rentals.  

For reference on flooring, I had the local big box store come out last year for a quote.

Our solution combines real estate data with the power of AI to help users analyze their deals faster and with more confidence to make better decisions and buy better deals.Reading your post gave me the idea of our tool not only being for analysis but also a way to track deal flow and a place to store all the things you mentioned.

Be ready to start conversations with the people in the grocery store behind you in line.

Virtually walking a property is a recipe for disaster.Honestly it blows my mind that someone will spend hundreds of thousands of dollars on a home  (probably their largest investment) and never visit it, but will run to the store to try on a pair of pants for $30...

Does anyone know if I can and how much I can charge while I store items left behind by my former tenant? 

Again, the BiggerPockets store has some books for this or you can learn by watching podcasts, reading blogs, and interacting on the forum.

Not worth my time to chase them down or store their junk and if they left it behind, they clearly don't care enough about it.

Buy a vacant piece of land close by and offer to store his stuff for free until the house sells. 

Purchase price: $650,000 Cash invested: $75,000 First industrial development, project consists of 2 warehouses with a trailer drop yard for indoor storing of dry goods & refrigerated