The terms widely vary between lenders and even on a commercial loan I haven't found any that require 25% down.

One of my investors has 3 million committed to going far and wide with me, she is selling a resort in the Carolinas that has a 1% cap, makes 36ka year, she is like a mom to me and I want to get her in on these deals. 

Look up your local and state landlord-tenant laws (because these vary widely by jurisdiction) about how much notice is required to raise the rent and any limitations that may apply. 

The only thing I can determine from it is that $210-$300k is an awful wide spread and may need to reevaluated, and I don't know of many houses you could pick up at the price you stated and turn it into a quarter-million dollar home. 

The great thing about owner finance is that there are a wide range of terms that can make sense and you can get creative.

We are still in a nation wide housing shortage which will take a few more years to correct.

@Mohaned Mustafa,Talk about a wide-open question! 

Cleveland has been the  " hot spot " for world wide investors for about 10 years , heck I sold about 240  props to investors from Israel, about 500 overall . 

I joined that city wide community Facebook group and found great suggestions.

If it doesn't you can pick a market anywhere that does with some world wide web research!