Overpriced Treasure Item Fails to Reach Museum or Find a Buyer, But Treasure Hunting Out Looking for More

A Norfolk woman dug up two Anglo-Saxon gold artefacts in fields near her home near Aldborough, Norfolk, three months after taking up the hobby (BBC, 'Norfolk treasure-hunter puts finds down to 'beginner's luck'...' 24 June 2020). The news item concentrates on the human interest aspect: "inherited a metal detector", "a case of "beginner's luck", and skips the archaeological and conservation issues:

Mel Hollwoger, 54, unearthed a sword scabbard mount and rare gold band [...] The mount was valued at £25,000 and both have been declared treasure [....] The band, which resembles a ring, is expected to be valued at a price similar to the early medieval cast gold and garnet pyramidal mount, which failed to reach its reserve price at auction recently [...] Norfolk Museums Service wanted to buy the mount but had to withdraw following its valuation by the British Museum. [...] The lucky detectorist said she was hoping to find "something Celtic" next.

And who set that reserve and on what grounds? The real headline should be that the Treasure system needs fixing so this sort of thing stops happening, as the market becomes saturated with disclaimed metal detected Treasure items.
Until then, since these folk invariably claim they are "in it for the history" and not the money, maybe standard search permissions could include a clause about both finder and landowner agreeing upfront to donate free of charge all finds declared as treasure to the museum that requires it