The Open Source Cartridge Reader (OSCR) is a versatile tool designed to help preserve video game cartridges and save data. Developed by Sanni and the community, this device allows users to back up ROM files and save games from a wide range of vintage consoles.
Yeah at least with their parts lists the material cost is ~$134. So even the places selling kits for $150 are offering a pretty good deal for putting it all in a box for you. ( I assume they’re able to make some savings buying in bulk but still)
Though the benefit of open source is if you only need some of the connectors you should be able to save on the ones you don’t need.
This seems to be targeted at specific people though, who have many of these systems themselves or will be backing up saves as a service for others. For instance I really only need my GB/C/A dumper. An NES dumper would be neat but if I needed that bad it I’d have it, they’re probably $40 last I checked. If you need more than 3 of these systems though the $150 kit would likely save you money.