There are 3 different types of Vendors in the Underground.Selling shards isnt one of them
>The first group of vendors are those who accept the player's treasures and give them spheres in return.
> The second group of vendors are those who accept spheres and give goods in return, and vice versa.
The last group of vendors are those who accept spheres and give traps in return, and vice versa.
Source
I love Weird things ¯(°_o)/¯
