You can find "ready to drive" Factory Fives all day long for under $30k. Assembling / building is another matter altogether. FFR is a great "first cobra" and kit for someone doing a build. Lots of them are. If you were to buy a running FFR at the right price you could get a taste for what this is all about, get to know other cars, what you like / don't like - then sell it for "the one" whether you decide to do a build or move to something different. The things that are important to me now in doing another cobra are different from when I did my first FFR. I have Kirkham / ERA taste but a Factory Five budget. With all of these kits it's possible to end up with a nice car.
http://erareplicas.com/427/profiles/index.htm
http://erareplicas.com/differ/index.htm