Lowered drop rates could also be the culprit for the sudden increase of all items in the market.
If you're looking for a farm spot, mine is 5-1 vh on solo mode. You get lv4 mats, possible elstones/acc, trash equips. Those trash equips could be dismantled giving you lv4 upgrade stones. You can also do the repeatable potion quest while farming that map.
It takes me around 7-9 mins to make 1run and an hours worth could give you around 1m+ worth of items (not counting gains from elstones/acc) depending on your luck.