1GB ddr3 sodimms are pretty much free/garbage(friends, IT at work) due to being outdated and too small for anything, or $4 on ebay including shipping if you cant be bothered to ask around.

Those were just first random links from ebay, you can get better deals if you search harder, for example EU $15 http://allegro.pl/org-sprawna-plyta-glowna-lenovo-x220-core-... whole lower case +wifi +bt +cooling, one usb mechanically broken (out of 3 sockets, 9 more usb available if you solder directly to motherboard in strategic places like camera/mpcie/fingerprint/expresscard/dock connectors). Thinkpads can boot from SD card just like raspberry pee. You boot without keyboard by shorting one pin on keyboard/dock/debug connector.

did I mention full schematic? http://plan9.stanleylieber.com/hardware/thinkpad/x220/x220.s...

mostly open source firmware is also available https://www.coreboot.org/Board:lenovo/x220

Thank you for your reply. I made some off-topic comment a couple of months ago on HN about the lack of inexpensive, full x86 compatible SBCs. This gets close to the mark, especially if I can run the bare motherboard or something close to it.

As an aside, the schematics really take me back to a moment in the late 1980s. Radio Shack sold Tandys and TRS-80s at one point, and I remember an especially thick series of binders full of the system schematics for one (or some) of the computers they sold. I was too young with no money of my own then to buy them, and now I really wish I knew what that was so I could find it on eBay. Little did I know that was the end of an era, and not something I'd see the likes of again until today.