My first arranger was a Casio tone CT 401..I can't find a picture , but it was their high end model in 1980-1981..I paid $700 for it.
After that a Casio CT6000, CT7000.
As a dealer I also had the Casio super model CT8000..

The first "Pro" models I had were Solon TSR4, MS100[mid 80's]..Early 90's I switched to the Rolands and Ketron X1 in 99'..