It's probably not interesting to talk about TCG items in this respect because many of them are gold cap items and are available in quantities that don't seem to correlate with the actual supply of redemption codes. So, let's put that aside.
Got a Gutrender up for about 200k.
Got a Lesser Parry recipe in the vault, which for some random reason is worth 100k these days instead of 250-500k. *shrug* So the Gutrender might actually be my most valuable item at the moment.
The Guardian Cubs are headed up there though.