This is an extension kit to a well designed and well adopted embedded system. The OPs complaints to me read as: nobody wants these features because the stock mo

This is an extension kit to a well designed and well adopted embedded system. The OPs complaints to me read as: nobody wants these features because the stock model works for OP, and that the price was jacked up to cater to an industrial market. I addressed the second point above - to stay in business, hardware costs money. On the first point, the product definitely provides benefits over the stock Pi. If you need those improvements, you need them. The $35 model will die if you plug in a logic level that isn't 3V3. It certainly won't handle standard RS-232. It doesn't have a proper power jack - either USB Micro or two GPIO pins (no latching). It also doesn't come with a DIN rail mounting system, nor an RTC, nor a UPS, nor a good voltage regulator. Some people might want those features (I've worked jobs where they would have been useful.) Also on the buzzer front - not all DIN boxes are in factories. They're used inside buildings for power distribution and fuses, in greenhouses to control irrigation systems. These aren't necessarily noisy environments.