I have a brand X digital fish (hanging) scale (similar to this one )that I picked up here in the US at TJ Maxx, a chain of retail overstock stores (mostly clothing and shoes). This one was in the Men's Gift section, along with minature pool tables, odd golf accessories, and drinking kits no one wants. (Marshalls is another chain that comes to mind.)
Mine (as well as others I've seen) doesn't display weights less then 8 oz. (and it displays weights in .8 oz (or .02 kg) increments above 8 oz.) You can be creative to get weights less than 8 oz. if need be.