There is a lot of excellent advice on the internet from fellow boat-builders about why one should buy instead of build. I did read all of that advice, honestly. In the end, I felt that building this boat is something I really wanted to do for the fun of it. Beats sitting around playing video games, that's for sure (but more expensive).
I'm certainly not building to save money -- it was pretty clear before I started that this would be a bad idea, and by now it's quite crystal clear that I'm spending a lot of money. As a novice builder I tend to be a little sloppy on new procedures at first, and I don't always economise on materials as much as I should. I think these are just skills you learn, and I am getting better as time goes by.
Why an F22? Pretty easy there: the boat had to be a trailor-sailor. And I wanted it to be a lively boat, not something slow. My wife and I are novice sailors, and I think we will both enjoy the experience if we're on a more or less even keel. And given the light weight, I won't need a new tow vehicle to pull the boat. And while there are other light-weight trailerable multihull designs out there, Ian Farrier's boats have a great reputation, and this was a chance to build his newest and (hopefully) highest quality design.
Finally, I have to give credit here to a boat builder whose web site I spent many hours perusing, which first gave me the notion that someday I could build my own boat, and got me interested in multihulls. That would be Tony Bigras, who had a great site detailing the construction of his 50' aluminum catamaran. Tony's site was quite simply inspiring. Unfortunately, that site is no longer up, which is a shame. Thanks again Tony.