Forza 1 at launch was £40 from a GAME store, sold it around 360 time, bought it again 3 or so months ago for £1.99 on amazon.
Forza 2 LE was £49.99 from GAME (yet again, was living away from home so had to use a store) and was amazing.
Forza 3 LE was £39.99 from Blockbuster.co.uk due to a price error making it the same price as the regular edition, they honoured it but it was delivered 3 days late and has a smashed in corner
Oh and when my sister bought a new fiat stilo she bought the xbox branded forza model and still drives it around today, it's weird having a sporty black car with the xbox 1 logo on the sides next to the wear window, it came with an xbox and forza 1 which she sold off for a little money.