Your examples are more like colleges charging more tuition on out-of-state student, or tourist attractions charge lower price to locals, which are made public information. The context under this thread is talking about dual price that is deliberately taking advantage of information asymmetry, differentiation, or even discrimination based on social class and skin color.
I can't speak for Rome because I have not been in churches there but for the rest of Italy, 99% of churches are Free Entry and the few very famous touristic attractions have a single fee no matter who you are.
Maybe you are confusing paying for a guide as tourist with paying to visit the church.
Free entry - but for those going for the religious service. That's not me. At least that's how it was all around northern Italy few years ago when I visited.
My experience in S. Korea is different, if you are a resident of a certain province (I don't know what is that in Korean) you get a discount on the local tourist spots even if you are a foreigner or a S. Korean. So if you're S. Korean and live in a different province you pay a higher price.
