The price of all the spare parts to build an assembly will always be higher than the finished product, absent some crazy imbalance of very high labor and very l

The price of all the spare parts to build an assembly will always be higher than the finished product, absent some crazy imbalance of very high labor and very low parts costs. (Arguably, a block of wood that you can whittle a product out of would sell for less than the finished product, but anything mass-produced will have spare parts priced at some small multiple of the finished good price.) Why? It's incredibly labor-intensive and logistics-intensive to track and offer one M10x1.25x12mm bolt or one main PCB for a $30 product. When I'm mass producing 5K units, I need 5K PCBs, 15K bolts, 5K upper case halves, 5K lower case halves, 5K displays, 5K buttons, etc. and I can arrange to have them delivered lineside in kits or whatever form I need and I'm pretty much going to use up everything I order in a very predictable way. When you need 1 display and 2 bolts, I have no guarantee that I can sell all the spare parts I made and stocked, and each little fiddly item I have to have someone inventory, put away, fetch, box, pack, and ship to you. It's going to cost more or you're not going to get it. (Today, you mostly can't get it.)