When you want something that will help you keep your beverage warm, anyone with basic skills could probably fashion something out of bits and pieces they have lying around the house in about half an hour. Unfortunately, cooling stuff tends to be a lot more complex than warming stuff. If you want something small to help you cool a few drinks, even a simple beverage refrigerator can cost you $100.
For instance, how much would it cost you to buy something that could keep your drink warm? The simplest devices go for about five dollars. The simplest beverage cooler you could get to just plug into your USB port to keep your drink cool next your computer, something like the CoolIT Systems USB Beverage Chiller, for instance, can only cool it down to 7 degrees. and boy is it expensive at $75. Why, for about $30 more, you could buy a proper beverage refrigerator.
That's exactly what you should do – you shouldn't ever bother to buy something just to keep the one drink moderately cold next your computer or something like that. You could buy a full-sized beverage refrigerator each time you want something like this. There is no point to getting anything less. How they go about buying one? How do you know what makes for a good product?