The home appraised for 1.2M, the deal is anything the home sales for over 1M after the fix up he will split with me minus my costs. he will hold the home while I do the renovations, no home purchase necessary.My question is how do I find the ARV on a high end home so I know if this is worth pursuing? 

So here's a real life  question. 

I had the exact same question/thought of you and was curious.

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

I'm not saying you'll be working a lot all the time, but you'll regularly have late-night questions from people checking in, for example.

We'd love to help you and share our expertise with any questions you have.

I have one more question whom to write the mail to ?

You can even learn a lot from leads that don't book with you, if you build report and ask the prospect worthwhile questions.

So, maybe do 30-50% down, for better cashflow and make sure you have reserves for mortgage payments in case there's a rental market dip in the future.DM us if you have any more questions:)

This is from the State of Florida's website and here's the answer to the op's question.