I made an alaia a while back and it is really fun to ride. I too was daunted by the cost of a new board and the cost of paulownia wood blanks, so I just got cheap pine 1x3 boards from Home Depot. After I glued them together I planed the whole thing down to just about 1/2" thick, cut out the outline (1cm skinnier in the center than at each end), and carved out a concave like the Naish board. Everything came out nicely, but the board was way too flexy and weak (too thin) so I glassed the bottom with a 2" wrap up and over the rails. Nothing fancy, in fact it is kind of ugly, but the board is super fun to ride. It still has tons of flex for that "magic carpet" ride. I thought it would pearl super easy in the chop, but it just doesn't. As soon as I put my weight on it the board flexes and I end up with plenty enough rocker to keep it gliding along through the chop. For now I wax it, but I was to pick up a couple of leftover deck pads and stick those on for some more grip. It is a really fun alternative on lighter days and is always a conversation started on the beach in Kailua. Now that I think of it, I am going to head over there right now and get some alaia time!
Aloha