I would suggest you up your rate from 8% to 10% to help off-set some of that cost. 10% is doable all day long here in Texas.

The nice thing about the arbitrage business model, is the companies usually pay you a monthly rent, and then they handle all of the AirBNB stuff. 

However, our tenant turned out to be problematic—late payments, issues that led to an eviction, and additional repair costs before we could relist the property for sale.Now, after months of making mortgage payments out of pocket, we finally have an offer.

Begin by targeting distressed properties in gentrifying neighborhoods, securing financing through hard money lenders or private investors, and focusing on cost-effective renovations.

Even still, it could be said that I've still lost money due to my time on the tools instead of prospecting as a real estate agent (the cost of lost opportunity).If you can truly do 80%-90% of the work yourself (at acceptable quality levels) and you aren't sacrificing your time where you can get better returns for your efforts, then yes, it can work even up here in Canada.

And maybe diversify a little, invest half in a low cost S&P500 fund like VOO and the split the rest across 2 or 3 syndications.

Sometimes, buying an existing property can be more cost-effective and less time-consuming and maybe require slightly less permits, etc. 

I typically don't comment on other's businesses unless I know from personal experience.

Evicting them, even after purchase, could be a lengthy and costly legal process.

Definitely a bad way to do business.