How did Peter afford all the backpacks?

Playing through the 2018 game for the first time I’m about 50% of the way through with like 48 of the backpacks so far and it’s made he wonder how he actually afforded all these over the years? Peter throughout the story so far has expressed being broke and pretty much always struggling for money even mentioning that when he won that $100 against that wrestler it was the most money he’d had at that point. Now I’m from the UK so prices may be different but surely bags are around $5-$10 and I feel like that’s a lot of money when you’ve bought 55 bags just for them all to end up across New York

(more of a joke question I get it’s just for collectibles)