Networking and doing the legwork of marketing is really the only way you'll find off market deals. 

First off, congratulations on your condo's appreciation from $373k in 2018 to $450k now. 

I'm generating more leads than I can use and am looking to monetize them.Does anyone know of any platforms or marketplaces where such leads can be sold directly to listing agents?  

All of that is independent of one-off maintenance costs - for example, trimming my palms costs $100 a couple of times per year.

For the renovation i would call 3 contractors off of google and have them give you estimates for the renovation .

And I’ll know if I am getting ripped off in the future.

A contract for deed doesn’t transfer legal title, it’s a contract that states title WILL BE transferred when the loan is paid off, or a specific amount of equity is accumulated in the property.  

Is that off the appraisal value or the purchase price? 

I'd start off with reading Avery Carl's book "Short-term rental, long-term wealth" if you haven't already.

Trusting others and handing off work.