At some point I might regret telling people this, but the way I make some really easy lant is by combining supernus xeons into stacks of 10 eximius xeons. They sell for about 100k a stack most of the time. Most I've pulled for em is about 200k. Remember supply and demand though, the more stacks that are in the Auction Hall (AH) the less your going to have to sell them for if your looking for a quick buck. If your patient though you can make some great cash to get all that pretty shiny items you want.
*Note* If we all do this too much though, in game economic trends are going to naturally drive down the price of eximius xeons. Not completely bad when you need them at higher levels, but does counteract that quick buck.