Over here the AX80 is probably worth 300 - 350 euro, but often you see them sold for less (appr. 275) because somehow nobody here wants them. But it's unfair, just compare it to a Juno 60 or 106 which are in the same budget and the AX80 will win spec wise. And sound wise I think it's also stronger than the 106, but slightly less strong than the 60.
It's quite a versatile synth, but it's strongest for bass, pads and effect sounds. All in all it's a very deep, warm and woolly sounding synth.
As you can see, all parameter value's are graphically displayed with a led bar and a more precise 2 digit led display. Editing is quite easy: one button to select the parameter and one dial to change the parameter value. Akai designed it to look like - and compete with the revolutionary and popular DX7, but failed miserably; nobody wanted an analog synth anymore.
If you do buy one, see that the left 2 parameter banks can be edited (the ones for LFO and EG). Often they don't, because inside there's two IC boards, one of which handles the touch membrane buttons, and they are connected quite badly. Often these connectors are faulty and you'll have to either re-solder them or replace them with a ribbon cable in oder to be able to program the LFO and EG. It's not really a though job but I admit that I fucked it up so I brought it to a repair guy.
I'm not sure if you should get one, but I think you won't regret it if you do.