@Hamidou Keita I would recommend if duplexes are limited if you can get a 4-5 bedroom house and either rent by room for house hack or splitting a big house into 2 and adding a kitchenette and separate entrance as a more cost effective ROI option 

Quote from @Frank Barletta: It is more cost-effective and practical to install a large-size TV and get the Nintendo, Super Nintendo, and Sega Mini consoles.It comes with games preloaded, legal, and each to swap in case something breaks. 

Effectively offering more than 100% financing.  

Your referencing effective age vs chronological age. 

However, this is not really effective in the real world.

The rules are designed to prevent related parties from engaging in exchanges that shift high basis property for low basis property, followed by a sale of the low basis property, effectively "cashing out" without recognizing gain.If you sell a property to a related party as part of a 1031 exchange, both you and the related party must hold the exchanged properties for at least two years following the exchange.

Which would be more effective for pitching my Airbnb arbitrage business?

If you didn't pick a tool that quite obviously works because of a factor completely unrelated to the effectiveness of the product, my course can't help you, ..

The main issue is a consistent lack of effective management and oversight.

If I have to buy a last-minute ticket or spend $1,000 or so for notarized signatures at a consulate, then it has a significant effect on my choices.