Haved owned the 'Tag Heuer Indy 500' for a few years now. Purchased 2006 in the USA for under £500.00. Extremely nice watch; battery quartz function, with triple chronograph & shiny chrome finish. It is the flagship model of Tag's entry level Formula 1 range; has a flash appearance worth more than the cost. If buying on Ebay make sure you look for the whole package, original boxes look expensive to suit the watch, and make sure it has the international warranty card. This is a lifetime warranty. If you do your research fake's shouldn't be an issue, you'll get what you pay for. New RRP in the UK is £695.00, Look's like on Ebay a second hand one is going to set you back upwards of £300.00. Some wear and tear became apparent on mine, the numbering on the chronograph wore off, and the timer hand didn't reset to zero; sent it back to Tag this was rectified <6 weeks, as new. recently had the battery changed, the jeweller option to send back to tag was £65.00 - a bit steep. I opted for a cheaper option from a watch repairer, new battery, and pressure tested also for £30.00. It's as new working great again.
On the whole a great watch, looks the part, won't break the bank, reliable and sturdy. Can't see anyone regretting the purchase!
Check out the Tag website, it'll give you an idea of the exact look to compare with pictures on Ebay.