I have done quite a few different things, one of the best to find out who is doing the most volume is go onto good and search for the "we buy houses companies" in the area you are looking to invest.

Investors buying land to HOLD for either speculation or future development can just wait until the wholesaler’s contract with the seller expires and eliminate the wholesaler “markup”.  

You’re going to have to buy at least $1M (or whatever you clear after selling costs.), worth of replacement properties, not $500k.

What makes you question to buying another house? 

Here's the challenge: If the numbers work with a low down payment, why wouldn't an investor putting 20%-30% just buy it and could likely offer more?

Anyone ever buy out this way?

Now that house has been rented out for the past two years, and I want to buy another possible duplex or triplex to house hack.

Quote from @Virginia Frost: Investment Info:Small multi-family (2-4 units) buy & hold investment.

You lowered the amount you had/have to buy with your exchange.

Say he stays there 2 years minimum and then sells the property for what he buys it.