How do you spend TBT to get collectibles?

[Story]

I’ve done it once many years ago. Lol so I don’t remember.
Is there a shop somewhere where I can just flat out buy a collectable?

 

[LambdaDelta]

the shop is on the top-right part of the banner where the bell bag is

for buying collectibles from other users, refer to oath2order's thread here

 

[myow]

Probably worth mentioning too that most collectibles are only obtainable/purchasable through events & rare restocks of the shop.
Otherwise buying from other members is usually the way to go unless you're only looking for the ones that are always in stock.