How do people not keep things ‘just in case?’ !!
Consider when you last used it and how long you've already survived without it.
Consider the likelihood of you using it in the foreseeable future. Is the issue that you want to use it, but don't? So is a lifestyle shift what you really need instead of decluttering it? Are you going to commit to that lifestyle shift, new hobby or whatever it would take for the item to be used? If not, accept it's only a dream, not reality and let the item go.
Consider whether, if you didn't have it, there's something else suitable (or "good enough") that you already have which you could use instead.
Consider how much it would cost to replace it with a suitable item, if you found you did make a mistake decluttering it - eg they might be £400 shoes, but if you needed shoes in that particular style/colour etc would you need £400 ones or would £30 ones do and how long did it take you to Google search something suitable? That gives you your repurchase value and you've considered the ease or otherwise of repurchasing, which is also a factor.
Consider your income and decide if you made a mistake decluttering and needed to replace in future, could you do so without financial hardships? If yes, you can get rid, secure in the knowledge that even if you're making a mistake you can fix it if necessary and it's not the end of the world.
Today's out:
One blingy bobble hat with some blings missing. Total is 4216