Here’s a unique dual use mouse- it’s a standard USB optical mouse that flips open to reveal a digital scale inside. The $50 Optical Mouse & Digital Scale from American Weigh has a 500g (17.635oz) weight capacity for the scale portion with readability to .1g (0.005oz). The scale has a removable cover that flips upside down to become a tray for weighing things. There’s also an internal rechargeable battery if you want to use the scale without being hooked up to the USB cord.
VicTsing MM057 2.4G Wireless Portable Mobile Mouse Optical Mice with USB Receiver, 5 Adjustable DPI Levels, 6 Buttons for Notebook, PC, Laptop, Computer, Macbook - Black