This isnt as much an exploit as it is a money making strat. Start with about 100g, and then follow this.
This part depends on the server, but on my server you can buy a small radiant shard @ about 5-7g, so if there ever under 3g bid (or if BO is the same bo) and resell..
Thats a little bit of money, this is where it gets HUGE.
Search Epics. If any under 30g bid then BID. If the bid = the BO then bo. Bid costs less so stick with that. Never buy under 30g, with some exceptions.
If you buy an epic under 30g, you'll make a profit for sure, whether DEing into a nexus crystal or reselling. The other day I bought a nightblade @ 27g and resold it seconds later @ 40g. The next day I bought a Lifestone @ 40g and resold it seconds later @ 120g. You can make 50-200g a day EASILY if you devote yourself to it.