It is not cheap, 995 TP, but you get a lot of storage room back. And it is accountwide. Plus, it is on sale often.
What does it do?
Purchasing this offer will allow you to move ALL barter items from your inventory and shared storage into the wallet permanently. This includes instance and skirmish tokens, region barter tokens, festival tokens, taxidermy barter items, legendary item barter tokens, crafting instance tokens and crafted runic barter items. This offer applies to all newly created characters and must only be purchased once.
(Took this text from Lotro-Wiki)