True if you have the skills to make the bits then it's not too difficult, but I certainly dont.
There was a really good guide to fitting the zetec on the cheap with home made parts, but the site is now down.
You are right that with just building an engine on its own the pinto wouldnt be the cheapest to get 200bhp, but i was thinking in the situation if I wanted to fit an engine in a mkii i would also need to buy all the conversion parts and the pinto needs minimal extras to fit.