Thrice shall pay for... what?

[Inziladun]

Originally Posted by The Saucepan Man

I suspect that this may well be the answer. 'Third time pays for all' is a proverbial saying, apparently dating from the 16th century. And we know how much Hobbits love their proverbs, saws and sayings! As I recall, Sam also refers to the phrase at some point, as one of the many that his old Gaffer used to say (perhaps that's where Bungo picked it up from).

Ah! You're right about Sam saying it at least once.

'Gollum!' he called softly. 'Third time pays for all. I want some herbs.'

That after Gollum had brought him the rabbits, then water in Ithilien.