I want to buy a studentroom (very popular here, cash flow each month around 400) for about 80-90k.

Scale comes down to just a few items which I can tell you for free right here.1. 

Feel free to reach out if you want more insights. 

Purchase price: $425,000 Cash invested: $100,000 Converting resident to rental in a ski/lake town.

They usually have a free online portal for fraud ime.

From there you'll need to determine Debt Service (if it's a financed deal) and Capital Expenses, to then calculate Cash Flow.The Cash-on-Cash Return (CoCR) will just be Cash Flow divided by the All-In Investment (Purchase Price + Renovations + Closing Costs + Wholesale Fee).If you're wholesaling these deals, I recommend you aim to offer your buyers a Cash Flow of no less than $250/mo and a CoCR of 10% or higher.

But between you paying down your mortgage, plus the tax write offs, plus market appreciation it sets you up for having tens of thousands of dollars in tax free gains when you eventually sell it.  

The plan was to build an ADU to add sqft, bedrooms, and rent to increase ARV and cash flow but the cost to do so is too high based on the projected return.  

A lease to own approach will depend on how much Seller wants to cash out and eliminate the property liability.Good luck!

You could frame it as a way for them to get all the cash up front and not have to worry about maintenance or expenses on the property anymore.