Had a read at the article. Its an interesting read
However..
Acquire $112.50 USD worth of ETH for the trade collateral using traditional methods (Can’t avoid this step as I need to show the seller I have something at stake prior to trading).
For entering a trade, you need collateral (150% of the trade amount) in ETH. And for acquiring the ETH required for the trade, you need to trust a third party intermediary.
So what's the point here for using the dex
If you can trust a third party to buy ETH, you can buy BTC from the same third party entity.
I commented on this earlier:
All that is required is a small amount of ETH for the initial collateral. Because the collateral is returned after each swap, a person can repeat the swap to buy as much ETH as they want. Then use the ETH to atomic swap it for Bitcoin. No trust in a third party or counter-party is involved.
So you can build on the amount that you have already by using it as collateral to get more. Theoretically, you could have $10 of ETH laying around initially and do repeated trades (14 of them in fact) to eventually get $1000 worth of ETH. In such a case, you got $990 worth of ETH without using a trusted third party.