. $6000/10 year life span/12 months in a year= $50 per month for 1 item.

What expense items are the highest?

What I need is a maintenance service that can take care of electrical, plumbing and general handyman maintenance items that tenants might require fixing.

Our plan is to use my HELOC to fund the down payment, closing costs, minor refurb items, and furnishing the STR. 

There's a roommate currently left that is stealing all the items of the deceased woman that would probably need to be evicted or cash for keys.

If we assume that equal application of inflation, and we're JUST looking at inflation, stocks come out ahead (There are real life reasons why real estate might [& often does] come out ahead of stocks, we're JUST looking at inflation here, with a very simplified model).

Our plan is to use my HELOC to fund the down payment, closing costs, minor refurb items, and furnishing the STR.

If you size correctly, you have a chance to sell.The above two groups are generally two different products and business models. 

Are there some items that have been successful for others1.

Stanley Martin says they are renting out these models for 2500$ but I do not have proof.