I think some Chromebooks like the Acer C720 are usually the best cheap pre-built $200 and cheaper laptops to install Linux based operating systems like Ubuntu on. Chromebooks Firmware are not locked like many newer Windows devices which uses UEFI Secure-boot which sometimes prevents non-Windows 8.1/10 install discs and flash drives from booting up the computer to install an alternative OS like Linux.
Plus, Chrome OS is based on Linux, so most Linux OS like Ubuntu would most likely be compatible with the hardware on a Chromebook because they are both based on Linux.
Plus, Chrome OS is based on Linux, so most Linux OS like Ubuntu would most likely be compatible with the hardware on a Chromebook because they are both based on Linux.