G'day Cazme
Thems some pretty old kites there!!
Depending on how old the PL is and condition, it would be worth about $300 bucks. $500 seems like a reasonable price for the equipemnt offered but I will assure you that you will be looking at new (more modern) kites before long. Things have come along way since the PL Peels and such.
If you are looking for kites for you ATB you would be better of searching for some Second Hand De-Powerables. Know of a few floating (ha ha get it - floating

) around so fire me a PM if you need a point in the right direction.
Troy