If Seerus' Mats aren't, then why are these? Selling them makes life in this already easy game way easier.
Make SL Mats untradeable
The thing about it though, is that not a lot of players want to play shadow lairs.
Well, let me rephrase that- not a lot of players want to PAY FOR shadow lairs.
And here is how the prizes are distributed through say, gloaming wildewoods:
First time through: Cool looking armor piece + ability to go to more shadow lairs + bragging rights :D
Second time through: Other cool looking armor piece :D
Third time through: 20K crowns. Or crafting more armor? If you just want it for a costume?... slightly more interesting than other runs? :l
Part of what you're suggesting:
Third time through: Worthless material/more of the same armor. D:
Which in turn raises the cost of the first time through even higher- you now have to find players that haven't done the shadow lair twice, or whom are willing to hoard materials for no apparent reason other than that you want them to? I know I wouldn't pay to go through a shadow lair to get nothing. I'm perfectly happy fighting other stuff.
If you made the vendors pay you 20K for a shadow lair material, then sure, but otherwise, I'd like to continue making a profit on the occasional SL run.
You have to pay to play the expansion, so if you traded seerus fragments then what if you go up to some noob and say hey there's this cool 2* helm called fractured seerus mask.. (1*) they buy the mat, try to make it and find out they have to buy an expansion to get to the crafting anvil. Now they have a mat they can't use unless they pay or OOO makes och CE buyable..
sl u can get to without paying and people run it often so its worth trading the mats instead of using our CE for more runs.
I like your logic. The thing can go backwards too. If SL mats are tradebale, why mask fragments aren't?
In fact, there are 3 types of fragments (1 per tier) versus 4 lairs and 4 mats.
About the idea, SL gear isn't so special or powerfull. I don't think it makes a big difference. It's just expensive costume.