I'd buy that for $100 all day long. UFO Robo Dangar is an interesting & uncommon Nichibutsu shmup that runs on Terra Cresta-like hardware. PCB alone is probably worth $100, and you get a monitor to boot.
Perhaps Jeff (of Rotheblog) can chime in on this - that conversion Dangar cab looks to be in the style of those Orca/Falcon/Artic cabinets that he has written about that tend to house Mr.Do, Ladybug and other games.