Wouter,
I havent left anything out of my number, every tool purchased for the project, every part, every bolt, every piece of raw material is in that $10k number.
I paid a mold fee to Steve Clark for the use of his molds and he is spreading the cost for the molds between 10 boats.
So, yes, you can build a competitive A cat for $10k.
Dellusional - no
So, how many man hours? Wharram estimates 400 man hours for the construction of a 21 foot cat. At the risk of comparing apples and oranges, a used A cat is looking pretty good. The prices I've found over the last 4 days run from $6- $10K. If you buy the $6k boat and replace everything that needs replacing, you save a lot of time and have a proven hull form.