I think the prices of the zeds have stabilised now and all the large dropping is done.
Enthusiasts are holding on to them longer also.
What i would say, with no disrespect, have you researched the full running costs of these? You're budget seems tight to purchase one, just make sure you can afford to fix it in the event a clutch goes etc as that will be well in the region of 1k. I would rather pay an extra 1k for a lower mileage car which has been looked after and already had a decent clutch put in...
A high mileage car may require some work which may not be apparent at the time of purchase. We have had plenty of blown engines in the last while with older cars....
Tread cautiously so as not to get a dog.