Alas Babylon by Pat Frank was published in 1959 and is one of the grand-daddies of this genre. It takes place in Florida (lots on oranges and alligators). It's occasionally dark, but not too dark, and I thought it was a real page-turner that also has some practical applications.

Here's a couple money-related quotes from the book:

On the other side of the drafty terminal Ben Franklin and Peyton buzzed around the newsstand, each with a dollar to spend on candy, gum, and magazines. They knew only that they were getting out of school a week early, and were spending Christmas vacation in Florida.

I guess in 1959 you could actually buy a lot more for $1.

By afternoon the cash registers of Fort Repose were choked with currency, but many shelves and counters were bare and others nearly so. By afternoon the law of scarcity had condemned the dollar to degradation and contempt. Within a few more days the dollar, in Fort Repose, would be banished entirely as a medium of exchange.

This book is available on Annas-archive.li