Were A4 plotters that much of a thing? I'd thought plotters were usually larger format (A0-A2 sort of size) for engineering drawings etc. Also iirc they were insanely expensive compared with your standard microcomputer dot-matrix printer.
The most popular pen plotter, and sort of the "holy grail" among hobbyists for this sort of thing, is the HP-7475A, a desktop model which could accept A4 or A3 sized paper (or US A or B size). It cost $1895 upon release in 1984, so yeah, pretty expensive when compared to the $650 an Epson MX-80 (best known dot matrix printer) cost. But there was so much more to the plotter than its paper-feed technology; it was much more a precision instrument in a variety of ways.
