$600 isn't that expensive. If you were to buy a Japanese cat in Japan from say Yahoo auctions you would be paying these prices:
Genuine Nismo cat: ~ 63,000 yen - $785 + postage + duty + GST + agents fees
Apexi super cat: ~ 53500 yen - $666 + postage + duty + GST + agents fees
SARD cat: ~44900 yen - $559 + postage + duty + GST + agents fees
So $600 for a proper cat doesnt seem so expensive to me.