For me, while I've made a couple alky stoves etc... I bought the BB Ultra because someone else had worked out all the kinks, it is spot on in efficiency and it works so dang well. I could spend hours making one, and while the value of DIY is different to each, for a wood gas stove it didnt pan out in the calculations of what two hours of work would mean to me in dollars . I am VERY glad I just bit the bullet and dropped 100 on it. It really is a sweet stove. I knew that no matter how close I got, I'd always wonder about size of holes, stability, flow etc... every time I cook. Now I just pull out that sexy beast and enjoy smoke, flame and food. But obviously, my skill is nothing what yours may be or 99.9 % of the others on here. So YMMV. When I cook though, I dont want an 8-10 min wood fire turning into 20-30 due to my design..... would aggravate me.
Cheers and good luck. If you make one, keep us posted.