This computer is an investment ,
VERY RARE !
http://www.trademe.co.nz/computers/vintage/auction-727695185.htm Some types of computers will never be worth anything, and the A500 is one of those types, desktop powerpc is another

can anyone help me understand the $700+ , its not even an A600 ?

all jokes aside maybe there is something that would distinguish this computer as Rare or valuable but I cant see it ? Saying A500 is rare, not something I can take seriously, unless rare means easy to find ? or collectors of A500's are a rare breed ?