I miss jumble sales! They're so hard to come by these days and it's such a shame.
The next village over does one or two a year, but they don't get a lot of donations so I see the same weird unsellable things every time

There's a really good Scouts jumble sale 2x a year that I drive at least half an hour to another county go to which is just like the ones I remember from childhood - heaving great piles of clothes for pennies just separated out into adults & kids, small bric a brac on tables round the edge, a table of books in the middle and bigger items outside. It's chaos, it's cheap, and it's so much fun! People queue for ages to get in (costs 50p for adults) and fill multiple bin liners each - the scouts must make a good chunk of cash. Definitely need sharp elbows for this one!
I've had some fantastic bargains from there (best was 50p linen jumpsuit - I wear that all the time).
I guess there's a lot of effort involved, not to mention the storage space required, so there a fewer now.
Blissfully, I have never seen an obvious trader/reseller at the jumbles - I do see them haggling at bootsales and in charity shops though.
Can you find jumble sales where you are? How do you find out about them?