@Tremblingmadness - Toast have an ‘archive’/sample section in their shop in Shepton Mallet. That’s the only one in the UK as far as I know. Some of their sale stuff/faulty goods/sample stuff ends up there.
The rest of it I imagine as piled into some kind of warehouse clothing Tardis at Toast HQ in Wales.
Every now and then, towards the end of a sale, random items from years ago, (presumably dug out of a cupboard somewhere), make brief appearances on the sale site - usually at about 3am. It’s all a bit weird🤣