You'll have to make your offer appealing in some other way.

The price started at 120k and I counter-offered 90k to which the seller was going to accept.

We offer it at TFSB but it does require the basics like qualified credit score, DTI ratios - Must have W2 or (2 years of 1099 income) to qualify.

If I have a property well below market, I would offer a more agressive rate to try to bring it up to market asap.

Multifamily offers steady income, scalability, and tax advantages, though it requires more upfront capital and management skills.

I’m not looking for cash flow per se, but I’d like for the investment to justify taking out of my professionally managed stock portfolio which did 20% this year. 

Apply the 70% rule to determine your maximum allowable offer, then negotiate and get the property under contract, ensuring your agreement includes inspection and financing contingencies.Arrange professional inspections to uncover any unforeseen issues, using these findings to negotiate concessions or confirm your repair budget.

That is why we just offer cash to key even they owe thousands since we all know it is lost money. 

There's also a point about intra-miami, my place went for over list and had several exploding all cash offers within 72 hours.

Some areas of cities have older stock.