I can get 1541A for around A$20. They are original Philips parts.
I also pulled out 2 TDA1541A S1 chips of a PCB - old Marantz player which insides I got from a friend of mine. And they do sound better. However, I was able to select 1 good sounding chip out of 6 1541A I bought just by listening to them and comparing with 1541A S1. The other plane A versions sounded nothing like S1 version.