We are not talking about buying a high end bicycle so you will not be carrying a big roll of cash when you go looking for a bike off CL. In my area, lightly used cruiser bikes are very common at garage sales. That's because a lot of people buy them and discover they are a lot of work to pedal because of the fat tires and heavy bike weight. The get left in the garage for long periods of time and eventually sold to make room for more stuff.

There's a way to look at CLs across a wide area of Florida. There is one guy who shows up in the Tampa listings with many bikes. Looks like he buys used bikes and refurbishes them. They are in your price range. The Diamondback Tess for $70 was sold new by REI. Sells for about $200 at current retailers. Obviously I don't know anything about the seller but it may be a place to look. He posts every day with a different set of bikes. If it says (Wesley Chapel / N. Tampa) for the location, that's him. There is another multiple bike seller with the location New Port Ritchey doing the same thing.

Good luck.