Some items are missing from the RealmEye current offers page for no apparent reason.
Someone recently was trying to sell me a yellow drake egg instead of an orange one and I think it’s because he couldn’t find a slot for a yellow drake egg.
The the missing keys or tradable items are:
yellow drake egg
purple drake egg
snake oil
healing ichor
treasure map
pirate cave key
forest maze key
spider den key
sprite world key
totem key
most gumballs
& most wines.
I just believe these items should be put on for consistency.
Some other reasons could be that you’re trying to sell a CoTT, complete a drake egg or wine collection or you just want some low level dungeons.
EDIT: Removed green drake egg & added gumballs.