Buying the house I rent w/ a HELOC w/ seller financ? Insight pls!

[Mario Tinsley]

Looking for insight with this deal, please! I currently rent where I live. I sublease out the house by room. It's a 4 bedroom 3 bath. But I also rent the finished basement part as a room too. So I live in 1 room and rent out the other 4 rooms. I was offered to buy the house via seller financing. The 3 bedroom 3 bath across the street just sold for $340k. Other similar homes on the street just sold for $310k-$340k. I would be able to buy this house for $310k. 30k down payment, 2.9 interest rate at a 30-year amortization with a 10-year balloon. The house was built in 2002; the roof and furnace were replaced this year, a new built-in microwave and dryer were replaced as well as the AC was serviced last year. I've been living here and renting out all 4 rooms by rooms for 4-5 years now successfully. I own another rental that I have a HELOC on and considering using $30k from the HELOC as the downpayment for this deal. Do you guys think that's a good idea? Should I use some of my HELOC on this? Am I missing something? I have attached a spreadsheet with the exact real numbers of how the deal would look if I move and rent out all 5 rooms. I keep the room listed on FB marketplace & I have people contacting me almost every day to rent a room out. (PMI on this spreadsheet is canceled out because it's seller financing so there's no PMI). I think I can actually get another $100-$150 out of the rooms in total, and I think the utilities are about $75-$100 higher than normal. and I am budgeting for Capex and maintenance though I don't anticipate anything will go wrong since there have been major repairs recently and it's a newer house. I also may be able to mitigate snow removal/lawn and the maid, that is just an idea right now, we do not currently have those services.