I've received the question on other boards on what it costs to build a Spec Focus car. Here's an outline of what goes into a typical build, as well as some per event breakdown of costs. This car was built from scratch, so it includes the cost of the car (salvaged, but already repaired).
There are some places where money could be saved - I probably overpaid for the cage, but it was built 100% to my specs by the best builder in the Mid-Atlantic. Didn't need to get 3 sets of wheels, and some of the other pieces (rear subframe and others) could have waited. But it's probably a fairly representative look at what it takes to build a 2.3 liter car. Zetec cars and motors can be had much more cheaply ($1k for running cars in Virginia), so there's a lot of affordability out there if you want to go in that direction...