Strange that two bidders were convinced of 'it's value'. Both seem avid collectors. Closer inspection of the dagger pictures suggests it is solidly constructed, the blade appears quite thick.
It does seem to have some age ,but the pictures are poor.
Perhaps a good weapon to use... in a warehouse full of magnets
If this is truly a weapon, then the reason for the use of bronze (brass, as stated in the listing) for the blade might help to ID. All I can suggest is religious reasons or a maritime use
Regards David