Was there in 05. Nothing requires any payment. I am guessing just the usual costs for tourist destinations - concessions, knick-knacks, get your picture taken posing in the grotto, etc.
Highly recommended though - talk about otherworldly.
I would imagine the shrine also gets offerings from the many Masses attended there daily by pilgrim groups.
I missed the digital pilgrimage due to this being a busy work week with US Tax Day in the middle, but they had a nice Rosary with the Pope live from there not long ago.
I will send them a donation.
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