On your points about prices being ruined;
Dragon hatchets being cheap - How is this a bad thing? This item is a stepping stone for new players and just because you used to make more money from it, doesn't mean you should forever. Besides the hatchet drops were never the main source of income from DKS. Most final bosses members didn't even sell their axes pre-instance, instead we gave them all to Phippzy since he had a collection and it wasn't hurting us gp wise to not sell them.
Pure essence price isn't ruined. - There is nobody selling pure essence ATM, I sold 350K+ of it a few days ago. There is a buy offer for 150k pure ess at 4.6k ea. Besides you only get ~10k-20k pure ess for 1K prime kills, which really isn't that much. But my point is Pure isn't is not hard to sell nor is the price far lower than it was pre-instance.
Ruined ore prices - ??? Ores cost more than they did pre-instance, purely due to demand. I had over 100K coal I was trying to sell for 2k ea, never sold any in over a month. Then instance came out, a few weeks after I stuck 300k+ Coal in g.e for 5K ea and it sold. I also recently sold a bunch of other ores for more than they were pre-instances.