Actually, there's some correction here. The above posts have it mostly correct.
1. You get 2 frozen feathers. 2 lesser demon stones and 4-6 scale fragments from the dynamic quests in both HM and CS, and again (if someone uses an orb) the same of each from the Kaari lord bonus boss.
2. Each of the 3 bosses has a chance to drop their per-ascension loot, plus 1-2 frozen feathers, some lesser demon stones , and silver scale fragments. Additionally the loot table now includes Hepta gem tickets.
3. The original merchant in CS sells Brilliant Ore Boxes for 10 frozen feathers, and Brilliant Radiance Stone boxes for 5 frozen feathers. They also sell resets, colored keys for each box at 1G/each and nightstone conversions.
4. The merchant of wonders has a chance to spawn in each dungeon and can sell Brilliant Ore boxes for 30G and Brilliant Radiance Stone boxes for 15G. He also sells mats (super expensive) , an outfit, and RNG gold boxes.
This means you could get 9-12 frozen feathers, but WILL get at least 6 frozen feathers if you do all 3 bosses. You could get up to 2 boxes of your choice if you're willing to part with gold and the merchant spawns with boxes both times. It also means that if you do just the main 2 bosses you should be able to get a box, for 1G (for the key) every other day...so your complaint is pretty weak really, given that doing the dailies literally gives you enough gold, even without premium.