Bazaar

There are a lot of people who don't have and don't really want to grind the required crafting level to unlock the q210/220 mission tier

Similarly some people have a lot of one mat and no desire to even out their mats

Alternatively, some people have moss for plants and they don't really like to dig so...

I sell quite fine from 200-300 at Q's over 150 and I am not above buying all 100 dapper mats and selling to Notso for 200 :P