It’s no big deal. I had to replace on and I think I paid $60.
Had to order a replacement power cord for a work HP laptop... was $90. Opted for a 3rd party adapter for $20. Worked great for a month, then overheated and quit working. Just glad it didn’t fry the laptop (as I have read stories of that happening).
As far as OEM chargers, Apple’s are not way out of line with most makers The problem is the proprietary connectors (and accompanying technology) they have historically used which made 3rd party products difficult (and sometimes dangerous).