At this stage anything used that small has been almost flogged to death. I would not be going for a used drive that small as it will be really really old and probably have a long time on it.

but if you really do want one, I may have one in my pile that I need to get rid of. where abouts are you?

That's a good consideration, with RAID1 across 3 drives should reduce the risk even with these second hand drives.

I'll probably move to larger new drives when I upgrade the server in the next 12 months

I'm in Auckland, around the city and West Auckland 

Thanks managed to get a set from a geekzoner