Value of a 1988 chev camaro iroc with 270,000 km

That is a lot of mileage or whatever you want to call it in Metricland. You can try the collector car valuation sites like Hemmings.com or Nadaguides.com (look under "Classic Cars"), you can also try all the IROC Camaro forums online as well as price compare on Ebay and Craigslist/Gumtree and so on. In the US midwest, that car would not be worth much, you can get them pretty cheap, especially as parts cars. It really comes down to options and condition.