Seller financing vs conventional

[Jared Hottle]

Anyone have any good rules of thumb or calculator for the break even point between seller financing vs conventional mortgage?

So if someone offered seller financing at a higher rate, higher purchase price but 10% down vs a bank where I could get a lower rate, lower purchase price, but higher down payment 20%

Essentially I am trying to see what I am paying in opportunity costs of choosing 1 over the other. I know that is vague but I am having trouble seeing what others see in seller financing. I understand the less cash to close but if you are “borrowing” the 10% extra in cash costs you more principle and higher interest where is the break even point.