ServBot (Level 11)
Man, what a unique looking machine. Pretty interesting design for 1979 and 1980. I'm sure there's someone on eBay looking to buy one, or a collector who keeps his eye out for something offbeat. I couldn't begin to guess what it would go for, though. Sorry.
Did you get the joysticks that came with it? Or any cassette software? It seems pretty useless without any tapes, since the BASIC language has to be loaded from tape each time you want to use it. You might check where you got it from and scour the old tape racks.