Welcome to AAPK. Looks like a nice knife but far from mint condition based on what can be seen in your pictures. What Greg has said is correct so I'll not repeat it. Case made literally millions of that pattern during the 20-plus years that stamp was used.
Our best gauge of current value is the worlds largest auction, eBay. Do an advanced search there, for sold listings only, of Case XX 6347. Confining your search to sold listings eliminates those listings where the seller is asking for an amount but the item has not sold.
I did a quick search and found a Case XX 6347 HP that looks to be in better condition than yours, that sold a week ago for $86. https://www.ebay.com/itm/Case-XX-1940-6 ... 7675.l2557
. Here's a picture from the seller's listing.
Adjust accordingly for condition of your knife against the sold knife and that should give you a ballpark figure for value of yours. You might do a more extensive search and find more examples.