I have sold a lot of q180 jewels in Dyron since the famous Haddo resigned. I make 'em all at 70% success rate so it doesn't cost me too many mats. However, I buy in all my mats and the price of the jewells reflects that exactly. I only make money when someone give me mats for free.
I currently don't dig myself, so I rely on supply (mats) and demand (q180 sets). This means I can buy mats at 3,000 each, but its pretty hard to find people selling that low. But there seems to be a balance.
The whole 'economy' that I rely on would be destroyed if someone dug their own mats and sold the jewels on very cheaply. Their 'expenses' are just their time but they are the ones making dappers, not I.
So you if want to encourage an economy, sell me yer mats

If you want uber cheap jewells, give me yer mats
Tember
Clan Omnis