My friend bought a Formula Ford for about $9K and raced the wheels off that thing! No, his car was not 'competitive' running against the later models with up-graded suspension bits, etc. But he still had a bunch of fun for a limited budget!
Hawaii Raceway Park is now closed, there are a number of Formula Fords and many other 'race cars' now in storage here in Hawaii, with virtually no local market value. Excellent deals can be had...