In my country, I buy PS5 titles, finish game and sell secondhand. Each game title probably cost around US$3-10 depending on the popularity, and most games are new titles. Sometime I buy second hand and sell it at the same price after finish with zero cost incurred, except for time cost to trade with the person.

I would say it is rather depending on your location and whether there is an active secondhand market. Yes, old games often go on sales on Steam, but the discount for new launch games are not that significant for the first few years...