cheapest 2004 ZO6 i found on autotrader.com in the US
http://www.autotrader.com/fyc/vdp.jsp?ct=c&car_id=242181495&dealer_id=915328&car_year=2004&rdm=1236438707540&model=CORV&num_records=25&systime=&make2=&highlightFirstMakeModel=&start_year=2004&keywordsfyc=&keywordsfyc=&keywordsrep=&keywordsrep=&engine=&certified=&fuel=&body_code=0&awsp=false&search_type=used&distance=0&marketZipError=false&search_lang=en&sownerid=70766&showZipError=y&first_record=26&make=CHEV&keywords_display=&color=&page_location=findacar%3A%3Aispsearchform&min_price=0&drive=&default_sort=priceDESC&position=top&seller_type=b&max_mileage=&style_flag=1&sort_type=priceASC&address=12309&advanced=&end_year=2004&pager.offset=25&doors=&transmission=&max_price=30000&cardist=273&standard=false