CoiltoSoil brought up another great point. The CZ-7, CZ-7a, CZ-70 are older machines but much like digital version of the CZ-3D. They have a digital screen with VDI, and are the same shape, etc.
Con to the CZ-7 series is the processor speed a bit slow. So if you notch out an item, you have to slow your swing speed. However, to avoid slowing down, you can run it in all metal (no discrimination) and then switch over to the target id when you find something.
Pro to the CZ-7 series is they are weather proof. By Fisher definition this means the control box is moisture proof, but not the battery compartment. Basically, you can use it in the rain or drop it in a puddle.....just don't take it diving.
If you are patient, these units come up for sale and sometimes you can get them with extra coils for a steal. About 18 months ago, I helped a buddy of mine get into the hobby when I found a CZ-70 with the 8" and 10.5" coils for $200.