I am sure people will come up with multiple strategies, one would be taking it over 'subject to' the existing mortgage until you're able to buy it from them. Give them a down payment, pay their mortgage, charge market rent, etc.
From a renovation angle, the standard math would look like this: ARV: $265,000, so 70% of that is $185,500, minus the $80,000 rehab, giving you a max purchase offer of $105,500 to the seller, AND you need to consider what you want your wholesale fee to be. Remember you have to explain the effort and expense you have to go through to to get that property up to 2023 standards. I use hard money lenders, and they all have had a 70% max loan of the ARV.
From the renting angle, some people want to stick to a 1%-ish rule - can the rent be 1% of the total price? Here, your 2-unit exceeds that. Don't forget though to account for vacancies, capital expenditures, maintenance, whether you pay any utilities, etc. That $500/month can shrink pretty quickly.