But for large multi-family, that amount hardly covers your legal fees for one transaction, let alone down payment, due diligence costs, lender fees, other closing costs, etc.

The lender does charge the flipper 4 points upfront, and the note represents 55% of the property’s ARV, so I’m not too worried about needing to foreclose if it comes to that.The lender uses his own capital for initial funding and then sells off the notes after that.

Understand that the cost to the investor is only the cash that's out of pocket. 

I am putting in a link to something that may be help, a cost of living comparison calculator (https://www.bankrate.com/real-estate/cost-of-living-calculat...). 

To be brutally honest i don't care if it's at cost, below or above, I only care what it is exactly and how much. 

This felt like they were turning me into their money-making machine.If they’re charging $10K upfront, plus $200 per month, and taking 50% of the profits, why aren’t they putting in 50% of the work or covering 50% of the down payment?

When you took in the increased cost of the build how did you arrive at that percentage?

They won't always be upfront about this with you but if know they're selling because they want to retire, that opens you up to different options vs if they're an investor just selling for profit.

Agents are also advising you to look for expensive mistakes (like checking the sewer which could cost 5-40k) and using their network and contacts to find homes off market or FSBO.  

And then also do you typically repay each partner their upfront costs from the profits before then distributing profits?