I beg to differ. (I'm unaffiliated and haven't donated btw). The Purism project is not directly comparable. They are doing substantial extra work and hassle and working with different parts. It's not about whether the machine runs a fully-free OS (System 76 running Ubuntu isn't even fully-free as Ubuntu isn't fully-free). It's about even the basic hardware drivers, BIOS, firmware etc. all being free/libre and the extra cost is covering the hassle and specifics of making that happen in the real world today.