If you refer to British general circulation Threepences, there are no rare coins.
British coins have been minted for well over 1,000 years. There are hundreds if not thousands of rare British coins from this period. Other than the odd "error" coin that might turn up from time to time, there are no general circulation decimal coins that could be considered to be especially rare.
The 1923-S Peace dollar is not rare by any means, circulated coins are only $37.00-$41.00. Typical Mint State coins are $47.00-$51.00
It is unlikely that there are any rare Two Pound coins. Can you be a little more specific about the coins, like a year and a design theme? Are they unimetallic or bimetallic, or are they Uncirculated or Proof coins made from a precious metal?
I bought most of my rare coins at auctions.
We cannot see you rare coins. Since we cannot even see your rare coins, we do not even know if your coins are indeed 'rare', what they are, their condition, when they were made - we do not know anything. Please specify in a different question what your coin is, the date it was made, and the condition it is in.
Rare coins are not common. Some rare coins that well known would be a 1909 S VDB penny.
The 1923-S Peace dollar is not rare by any means, circulated coins are only $37.00-$41.00. Typical Mint State coins are $47.00-$51.00
No.
None of the British London 2012 50 pence coins could be considered rare. The least number of any type that was minted was 1,125,000. There were 1,161,500 Judo 50 pence coins minted.
Generally not. Old circulated silver coins occasionally turn up, but banks don't make a point of keeping rare coins in stock.
Nope. They are worth the same as any other coin. They were made in the millions and are not rare.