So I've just tested everything - GP32s and GP2x are in perfect working order. Both Wiz batteries are dead so they only work whilst plugged in to the charger - and one of them won't stay turned on after the power switch is toggled. This was an early dev unit (also has two directional pads instead of buttons) which stopped working when the firmware was upgraded iirc. May be useful as spare parts to someone or if someone wants to try and debug the hardware and hack it back into working order - it says on whilst the power switch is held down.
As for prices, I have no idea what their worth and no particular intention to get rich off them and as I said in the first post they're basically going in the bin otherwise! So any reasonable offer will be considered .
Edit: each GP32 has an SMC but I no longer have a reader for these.
Edit2: the GP2x still has the dreadful F100 nub for the control stick so it's extremely hard to get it to register left - though if you take the numb off the underlying switch is clearly working.