I bought my Indy 500 almost two years ago for $3600.00 with no cabinet fade and a completely shopped out playfield. It's a great game with a lot of things to do. It's definitely underrated, as the game plays very fast, similar to the Getaway which I also have. But Indy just has more things to do, and is more challenging.
I would pick one up if the price is right as they are difficult to find. You sometimes will see one for sale on Ebay, or better yet here on pinside.