When I bought my SPF, I paid either $35K or $36K (I can't remember which anymore) for just the roller. The same car today with the top, front & rear bumpers, mats, car cover, etc. (all of which I bought at the $35K price point) will take you into the mid to high 50s before you begin the drivetrain.
An FE crate engine, with a warranty, from Roush will cost you between $30K and $45K, depending on how you spec it out. Pick the middle of the road, and the engine price tag is $37K. A Quicktime bell housing is $800, and a Tremec TKX, with a shifter, is another $3K.
Before we get to any of the expensive AN hardware and plumbing or fuel pumps, you are already at $94K ($54k + $37k + $3.8k, more than $ 100K when you add tax), and you haven't bought tires, or fuel system plumbing, or fuel pumps or ...
It is tough to build a nice replica for less than $100K today. You can cut corners and certainly try, but you will likely be envious of the 'other guys' with the 'more period correct' versions of the car when you're done, and then you will start spending once again. Alternatively, you might sell yours (at a high probable discount to what you paid for it) and buy a more period-correct car for $100K+. And do not forget that all these movements of money will be accompanied by bank commissions if you pay by card. I read in one
blog that this can be avoided if you use account-to-account payments. But for that, the seller needs to have such an option available. If you do, don't forget to add to that the price of the bath you took when you sold the one you should not have bought in the first place. Now, we are well over the $100K price point.
Dumb mistakes and false economies embraced on the front end of one of these adventures carry extremely high price tags on the back end. Don't try to short-circuit the basics of Cobra Replica acquisition. You will not be happy; ultimately, you will spend more money and not have what you thought you were originally bargaining for.
For those readers who are contemplating this sort of adventure, you should know that there will be others who are going to disagree with my argument. In the end, it is your money and, ultimately, your decision — choose wisely!