Not done any exact analysis, but purely from observation, and ball park estimate, I'd say that even in the last 2 or 3 years, prices have increased at all levels of the market. For example, what was £180 in 2020, is now about £240. Quite ordinary, or not desperately uncommon pennies are now routinely being offered at £200 plus. Although there are still bargains to be had.
One exact price I did notice was when looking at the change in prices for 1839 proof pennies last night, on Noonans site. I noticed that over the years three separate complete 1839 proof sets had been offered (with the Una and the Lion £5 piece included). In 2004, one went for £16,000. A year or two later, another went for £23,000. Then in 2011, yet another went for £60,000. But at the Noble auction last July - in the Verene Collection of proofs - just the Una and the Lion £5 coin itself went for £421,000 (converted from Australian dollar exchange rate). That is a staggering increase which is way beyond inflation.
How long will this continue? Maybe - very probably in fact - coins are seen as a safe haven in these economically turbulent times. Especially rare gold maybe.