Yep, the market has been consistent in the last 8 years or so, we just have a mindset (including a lot of the fans, not just the club) that we shouldn't spend more than X on a player. The market moves every year, 30m players become worth 40m then 50m then 60m. If we'd bought 3 30m players 3 years ago we'd he reaping the benefits now and still have over 100m in the bank.
There's no point holding on to cash, being twice as rich and then when you go to spend that cash, everything being twice as expensive, especially when not spending affects your results in the meantime.
We wouldn't spend 20m when the best players were 40m. Now we won't spend 60m when the best players are 100m.