As always it is demand that dictates the price rather than straight rarity. There are many more collectors for the few serious 20th century varieties than the far more numerous 19th century ones.
A more modern example is the Kew Gardens 50p - some 200,000 made I believe and much more sought after and expensive than the 2009 Athletics 50p, of which only 17,500 or so were made.
Similarly with the 1869 penny - for any date collectors, it is a must have and far more desirable than the endless minor varieties on the 1860.