I generally recommend the Canon Rebel XS. It can be had for typically <$120. Add to this a 35-90mm M42 helicoid, a couple adapters, and a 75mm EL-Nikkor lens, and you have a nearly unbeatable combo that can go full range of US coin sizes for <<$200. This is the basic recipe for the "<$400" camera thread, but without the high mag option, no tripod, and with current pricing and thoughts regarding the helicoid.
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