(in the UK) are there actually any commonly used hand tools that have become rare (for whatever reason)?
I'd say 'no' (including the router planes that Tasky keeps banging on about!).
As said above, interest in hand tools, no matter what the reason, actually increases the supply as tools that would have otherwise ended up in skip/on the fire/on a shelf are offered for sale.
To answer the OP's question, I'd say a collector will make a purchase because of the pleasure of ownership, thrill of the chase etc and needs no other justification. And if that floats their boat, good for them
I'd say 'no' (including the router planes that Tasky keeps banging on about!).
As said above, interest in hand tools, no matter what the reason, actually increases the supply as tools that would have otherwise ended up in skip/on the fire/on a shelf are offered for sale.
To answer the OP's question, I'd say a collector will make a purchase because of the pleasure of ownership, thrill of the chase etc and needs no other justification. And if that floats their boat, good for them