I am thinking of getting a 3dr cosworth to go with my other two. ( I seem to be loosing my will power and just buying all that I see

)
I was wondering how much I would have to pay for a good condition moonstone, with low comp engine, lightened and balanced, 330mm discs, ported head, T35, and leather interior?
It sounds good, but I don't know how much would be a fair price.