I think the best way to evaluate an additional investment is "Return On Investment".  

Retire , additional income , ?

If real estate takes up too heavy a weighting in your portfolio, then you'll be hurt more in a recession, deflation, hyperinflation, or depression.

There is an additional acre of land that can be subdivided and sold off that was once part of the original farmland about 200 years ago.

Also,  have a discussion prior as to your involvement if you would like to be completely passive and simply receive quarterly updates on your investment progress, or if you would like to know the challenges and why specific decisions were made along the way... latter of course takes additional time commitment. 

In addition to storage containers (which can be costly to have delivered depending upon where you are located) there are a few companies that actualy make a "portable" single storage building that are shipped flat and you tilt up the walls and have a rentalable "no building permit and no tax hit" unit ready to rent in a couple of hours.

Additionally, you can offset 25k of active income (like W2) with passive losses if have an AGI of 100k or less.

They have $750 stuck in the refund position with Airbnb and had to spend an additional $750 for another place (screenshots were sent for proof).

Grid) finds this acceptable as long as there is a written agreement in place prior to the tenant taking on the additional usage. 

So I would then return their 10k and they would have made an additional $4500 (900 times 5 years)I just want to make sure that I am understanding correctly.Also lets say they do want their 10k back in 5 years.