Roblox announced that creators must have a premium subscription to keep their UGC items accessories on sale. However, from what I’ve observed recently, some creators without a subscription still have their items available for purchase.
For instance this creator, a friend of ours: Rosprites - Roblox
doesn’t have premium for the longest time ever and still have his items onsale in his group.
(I’m only using the creator as an example, he’s not abusing the bug whatsoever)
Just a slight thing to add on to that, I think that it shouldn’t be that items quickly go off sale as your Premium expires because sometimes there are bugs when premium doesn’t renew automatically or the credit card doesn’t work with the payment gateway in some countries so I think that there should be a few days buffer before the items go offsale so that the creator can work with support to get those issues fixed.
(Speaking from personal experience with those problems.)