Funerary Weapon and Armor Collection
The funerary weapon and funerary armor can be bought for a measly few gold and elegies. Well, actually it's quite expensive. There are - of course - 18 armor skins and 16 weapon skins. The weapons cost between 36x Elegy Mosaic and 2 gold 88 silver and 72x Elegy Mosaic and 5 gold 76 silver depending on whether it's a one-hand or two-hand weapon. There are 10 one-hand weapons and 6 two-hand weapons. Accumulating all their prices you need 792x Elegy Mosaic and 63 gold and 36 silver.
Of course, there is one armor piece for each armor slot from foot to head and for each armor class from light to heavy too. This means 18 pieces as mentioned earlier. The price of these pieces depends again on which slot it fits in. With armor pieces that yield more stats being more expensive. The prices step from 6, 12, 18 Elegy Mosaic and varying 1 gold 20 silver, 2 gold 40 silver to 4 gold 80 silver. Additionally doing your achievement you get one full armor set.
That means we only need to buy two more. Buying a full set costs 12+18+6+6+18+12 = 72 Elegy Mosaic and 1.20+4.80+1.20+1.20+2.40+2.40 = 13.20, 13 gold and 20 silver. We have to take these times two since we get one through achievements and buy two. Of course, we can calculate times three if we assume we're not doing the other achievements to say what difference it makes.
Of course, there is one armor piece for each armor slot from foot to head and for each armor class from light to heavy too. This means 18 pieces as mentioned earlier. The price of these pieces depends again on which slot it fits in. With armor pieces that yield more stats being more expensive. The prices step from 6, 12, 18 Elegy Mosaic and varying 1 gold 20 silver, 2 gold 40 silver to 4 gold 80 silver. Additionally doing your achievement you get one full armor set.
That means we only need to buy two more. Buying a full set costs 12+18+6+6+18+12 = 72 Elegy Mosaic and 1.20+4.80+1.20+1.20+2.40+2.40 = 13.20, 13 gold and 20 silver. We have to take these times two since we get one through achievements and buy two. Of course, we can calculate times three if we assume we're not doing the other achievements to say what difference it makes.
Alright, so accumulating everything assuming we buy two armor sets and get one from achievements we need:
72 * 2 + 792 = 936 Elegy MosaicAssuming we don't do the achievements we need to buy three armors, thus we need
and 13.20 * 2 + 63.36 = 89.76 gold, 89 gold 76 silver
72 * 3 + 792 = 1008 Elegy Mosaic
and 13.20 * 3 + 63.36 = 102.96 gold, 102 gold 96 silver
Elegy Mosaic
The Elegy Mosaics drop mainly from legendary bounties, according to the wiki from meta events as well. Though I didn't really check that one. Anyways something I've seen that aligns with the information on the wiki is that each legendary drops [2; 25] (between 2 and 25 inclusively) Elegy Mosaics. Though the exact amount is not rolled equally. Getting more is increasingly rarer.
I don't have any data on this as of now but the fact is: you get at least two and at most, you seem to get 25. From experience it feels like on average it's about 4-6, I'd guess. So let's go with 5.
How Many Legendaries Need to Die?
Let's start with the low end. We need 936 or 1008 Elegy Mosaic and we have the worst luck possible only getting 2 per legendary. In this case we need to kill 936 / 2 = 468 bounties or 1008 / 2 = 504 respectively.
However, if we have impossible luck we will get 25 every time. This means it will take us only 936 / 25 = 37.44 that is 38 since there are no 0.44 bounties and 1008 / 25 = 40.32 which is 41 respectively.
Now if we go with our average of 5 it will take 936 / 5 = 187.2, 188 legendary bounties and 1008 / 5 = 201.6, 202 legendary bounties.
So, this means we do not only skip about 20 bounties by doing the achievements on average, but we also have to do a lot of legendary bounties. Luckily I'm done with it so, good luck to you if you haven't and happy legendary slaughtering.
Thanks, to all the commanders and lieutenants who did these runs on a near basis daily until the patch. They will probably continue in a few weeks again. I guess that's time to mentally prepare yourself?