I'd like more specificity about the ROI on an average flip. Can you help?

[Jimmy Wellman]

I've looked online for some information about the average % of the final home price vs. the price you purchase the home for and found that the home should be purchased for 70% of your home's final sale price. However, when I googled for the gross ROI, it said it was 27.5% in 2023 and I'm very curious about the net ROI. If the purchase price is 70% of the home's final sale price, what portion of the additional 30% is the $ spent on the flip and what portion is the average net gain?

I've heard 10%-20% is the average net gain but I just want to be more clear about it.  Is that the percentage gained on the portion spent on flipping or the percentage of the price you bought the home for + the amount it costs to flip?

Can someone help me with an example where I buy a home for $70,000 then flip it until it's $100,000?  

How much time on average will I personally spend on this 4-6 month process if I hire a team?

Thanks so much for your help!

-Jimmy