It can be a real eye-opener looking at past catalogues. To keep it topical, Cuff (1854) had a lot of Carlisle siege pieces including a few duplicates that sold from a pound upwards. Today these would go for a five figure sum. I know that one coin I bought 10 years ago for 1800 was part of a 4 coin lot in 1909 that sold for 17s6d!! Or the Henry VIII testoon that graced the front cover of the 2009 Coins of England, sold for £34K in Marshall (2004). In 1802 it was one of a 2 coin lot in the Tyssen sale which made a couple of quid.
Yes prices have gone up, but so has the number of collectors able and willing to pay for coins. 100 years ago, only the mint state or best(ish) known pieces tended to command top dollar with everything else seemingly going for a small multiple of face value, thus reflecting the relatively few deep pocketed collectors. Today, the average collector is unquestionably wealthier than those of yesteryear, and the population is significantly greater. When that is set against the reducing number of top quality coins available due to museum accessions and the fact that by and large the total number of coins available is essentially static, then there was only ever one way that prices could move.