DMP-40 DMP-40 Plumjelly (Computer) (OP) 11 Jul 10 19:15 I have received a Houston Instruments Hiplot DMP-40 digital plotter and I am wondering about how much this thing is worth. Anyone know its value? RE: DMP-40 kjpatt (Chemical) 20 Oct 10 10:11 I purchased one used last year for $40. We use them in the Lab connected to a lab instrument. Let me know if you'd like to sell yours. I always try to keep a spare if I see one available.