Just my personal opinion - get a mentor or a person who already has good experience running STR business, preferably in your area (but not 100% required). 

Hello,Looking for experienced developers' opinions on a deal I'm about to make in Europe, just based on the numbers.

Here’s our OPINION for the Metro Detroit market (use as a template for your target area!)

I’m curious if others opinions on how I do this.

It may be a tough pill to swallow if you feel you’re totally right, but you may be surprised at the LEGAL opinion rendered by counsel.  

The 10% vacancy and repairs, along with 5% capex in my opinion are pretty high. 

Happy to give you opinions on deals if you need to review some stuff.

Cannot thank everyone enough for all the replies—some differing opinions, which I appreciate!

Here’s our OPINION for the Metro Detroit market (use as a template for your target area!)

It could be a nice opportunity however I would be certain they will want you to make up the difference between $250,000 and whatever is left on the mortgage which btw in my opinion should be done with lender's knowledge and approval.