Ferrari makes money selling their road cars but also from royalties . Sponsors pay for most of the F1 team budget but that has nothing to do with Ferrari.Spa benefits.

The Enzo is much more profitable than any other road car offered by Ferrari. It will pay for its own developpement and then some ..

The idea of Ferrari making sub 100 000 euros would mean the death of Ferrari exclusivity as u would begin to see Ferraris everywhere pretty much like u see 996's and SL ..
Plus Why should they both ? they already offer a sub 100 000 euros car , the Maserati Coupe and Spyder .