2020 Tin of Lost Memories Case is a sealed tin from the 2020 Tin of Lost Memories set. A collector tin bundles a few booster packs with a promo card or figure in a reusable metal tin. Its current market value is $349.99, a premium sealed item.
It carries a market value of about $349.99 as of the latest update. The price has held fairly steady recently. Sealed products trade at a premium to loose packs because an unopened, untouched box is worth more to collectors and long-term holders.
Whether to keep it sealed or crack it comes down to your goal:
You can grab one from the live eBay listings above, or support a local card shop that stocks sealed Yu-Gi-Oh! product. Shops are also a good place to verify a box is genuine and in-hand before you buy.