The Mishna (Meilah 6:4) assumes that an etrog costs 1 perutah, roughly equal to 1 US cent.
The average etrog nowadays in Israel seems to cost about $10. Of course it's more in the US.
Thus, etrogs are about 1000 times as expensive now as in the time of the mishna.
That seems exorbitant. But a 100000% price increase over 1800 years corresponds to an annual inflation rate of just 0.38%. Which as any economist will tell you, is extremely low.
So maybe we are not getting ripped off after all.