So I was rewatching the Randomizer from the beginning and decided to keep a tally of the rupees that were lost due to the small wallet size. The final tally may be off a bit by like 20 - 40 rupees, as there were instances of them collecting only 1 rupee while travelling that I didn't record.
Otherwise the amount of rupees that lie at the bottom of the Great Sea before Matt and Michael got the big wallet comes out to... around 3100 rupees.
A good chunk of change but I honestly thought it would have been more. If anyone's interested here's the link to the spreadsheet that shows when each instance of rupee dropping occurred:
https://docs.google.com/spreadsheets/d/1AkHp9YmdSanakTUwfFcDQQZmNvze7X2K5tRJxpA5kXA/edit?usp=sharing
Of all the characters I'd like to see amplified I think Coco is top of my list. Coco's dust amplification, further amplified by Jaune, and I just want to imagine that it'd turn Coco's minigun into a rapid firing artillery cannon.
Jaune's Aura Amp
RWBY