You could offset your mortgage payment on a bigger house with the cash flow from the rental. 

Higher rent, guaranteed rent payment, collections and damage you just call their commanding officer.  

BUT there have been 24 late payments with the last late payment made in Nov 2024 and  0 paid on time.

That rental income helped us significantly offset our mortgage payment. 

What type of transaction fees should I be looking to pay and is there a down payment required?

A $100k Heloc payment will be around $750 per month (verified with el sereno client) and rents are $2,300 p/m so you tell me if this is a good idea or not. 

Personally, I wouldn't use a heloc to then go purchase a primary residence, unless what you can rent the current SFH for enough to cover the current mortgage (assuming there is one on the property) and the heloc payments.

@Charles EvansFrom my experience, having rental income of $1,400 to offset a $2,600 mortgage, leaving you with a $1,200 payment, is a manageable setup with an income-to-mortgage ratio of 28.5%.

He wanted 1/3 payment up front in cash and I paid him.

I could put a down payment for a conventional (20-25%) 550k duplex, but I feel it could hurt my chances of buying as many duplexes in a 5 year period (for example) if I go conventional VS an FHA at 3.5%.