The Premium Wallet Upgrade is on sale for half off (497 LP instead of the regular price of 995 LP) until Thursday, January 4th. It is expensive and very rarely on sale only. This is the best price is has been.
With this upgrade, many bound-to-character and bound-to-account tokens and barter items will be stored in your wallet, rather than taking up space in your bag or vault. It is considered an essential purchase by most players when they get to higher levels when there are many different barter tokens. The space it saves you would cost more than the wallet upgrade, especially if you have multiple characters.
Since my crafter accounts got to level 60 and went through Moria, I have been waiting for such a sale to buy it. One crafter had 13 items that went into the wallet.
You only need to buy the Premium Wallet Upgrade once per account, since it applies to all new or old characters on all servers for that account. It is not part of a subscription, so even VIPs must buy it at some point if they want it.
Once you buy it, you may need to move your existing bound tokens between the vault and your bags to get it to move them into the wallet. You will need to remember to look in your wallet for some bound items, like crafted relic barter items, since they will be moved directly to your wallet as you craft them.