Welcome @Mark Acton-Smith to the forum.
The 1971 two pence is one of the commonest coins ever produced. Nearly 1.5 billion were made as part of the decimalization process, so despite the rumour mill on Ebay and some social media sites, it is worth just the 2p face value.
The only proviso is that the scrap value of copper is quite high, so in bulk they may be worth more in metal content, but you have to find a scrap metal merchant interested in processing them. Also, it may still be illegal!
Sorry if that is a disappointment!