Appreciation is a long term game (10 years plus) because you don't know short term fluctuations.

Quote from @Amha Demissie: hello every one 😎  am new for this  but i listen real-estate rookie so i need some help here so i bought a single family house in 2019 in Massachusetts and now i want to buy a 4 family so around Boston   to buy a four family house is between 900.000-1.1m and i wanted to do a house hacking so i got 2 options to do take a HELOC for a 3.5 down payments and show for the Leander i have at lest 3 month reserve or pay 20% down at this point i don't know what to do    In my opinion a HELOC is very risky to use it as a down-payment, I have use a HELOC  before but it was during the 2000 when interests were fluctuating between 2.5 to 6 % max in HELOCs.

I will cash buy as I don’t really like their financing and don’t want to deal with currency fluctuations causing my payment to change month to month. 

Since you have 6 months to complete this process (this allows time for rehab, if desired), of course the interest rate may fluctuate a little bit, depending on market conditions, but there is not an intrinsic "1-2% higher" that I'm aware of.

The viability of an AirBnb strategy would also fluctuate widely based on where it was, ie at 116th and Kinsman vs on Dorchester in Shaker hts...

Yeah, various fluctuations but all within standard norms.

With a private loan, your partner can earn a 10% interest rate on the loan amount, providing a steady return without the complexities and risks associated with property management or market fluctuations.

I am also not a fan at all of HOA's, the fee eats the profit and can fluctuate.  

It is challenging to come up with revenue numbers given the fluctuations in the STR sector over the past four years and the vast increase in competition.

Acclimate the flooring in the room for a couple days, clean the floor well, don't put it right on concrete, don't do anything the manufacturer says will void the warranty (like adding on any additional adhesive agent), don't install in areas that fluctuate in temperature a good amount throughout the year, etc.