Yeah, an app isn't the same, but you'd probably say that $60 or $100 was expensive for an actual calculator, and HP still sells enough of them to keep them in production, even though newer models are more powerful. That's because the 12C remains the go-to calculator when teaching financial stuff (APR, amortisation, compound interest): the Amazon reviews provide a sense of how important a tool it is.

(Plus, the jailbreak apps people were working on emulators of their own, using the HP ROMs.)