This is a tool that is used to quickly analyze profitable deals just like the one you have described.Keep in mind; A large majority of lenders are hesitant, or will not, lend money on land, let alone construction costs associated with a "tiny" home.If you were considering using a VA loan (based on your profile picture) forget it. 

If there's construction management, that person takes 10% of costs for that. 

I will have the inspector look closely at the plumbing and toilets..

This often adds time to projects, as inspectors can be difficult to deal with.

You should hire a third-party home inspector to check out the house...not necessarily the one recommended by the turnkey provider. 

Cost of construction is very high so no one is building them and your rents should continue to rise over time.

In my day to day world of building new construction we often have to pay a little over market for lots to get them with competition being what it is..

So a combination could be done very easily.Combining this with new construction is tricky because of the timing issues but can be done using a reverse exchange.  

I ended up getting Superior Construction and Trinity Masonry out to take a look.

If so you will usually build more equity if you buy a fixer upper and do the work yourself.New construction is a good strategy if it’s a desirable area.