I have a chance to pick up a Lisa Mouse that was originally with the Lisa 2 I picked up earlier this year. I was looking on eBay and the prices are crazy. I am currently using one of my Mac Plus mice and it works fine, but I really would like to have the original keyboard and mouse. Is the value of that mouse really in the $300-500 range? I know eBay prices can sometimes be artificially high (listings at $500 or best offer), but the last one whole went for $550). I can get it cheaper than that, but just wondering why they seem to command such a premium?