If anybody has the time and cash to burn...
Try making a similar stove out of a double walled titanium mug. Try starting with Snow Peak's 21fl.oz (4.4oz) or 15.8fl.oz (3.5 oz) double walled tall stackable cups (http://www.snowpeak.com/gears/tw-stackablecupspage.htm).
---smaller seems impracticable. These are starting weights. Some material will be taken away, and a little added-so they should be close to a finished weight. The price (sans labor) is still less than a Bushbuddy.
1. Remove the handle assembly (if not starting with stackable cup)
2. Cut the majority out of the outer bottom--but leave the lip for strength.
3. Cut the inner bottom out about 1/2-3/4" from the bottom and replace with lightweight SS hardware mesh, or weave your own out of SS wire (or simply pepper the intact bottom with 3/16" holes, ala R. Faulkner's stove).
4. On the outside, Drill 3/8" holes 1/4" from the bottom all the way around w/ 3/8" gap (experiment for best dimensions)
5. On the inside, drill 1/4" holes all the way around with 1/8" gaps (or whatever makes it an even fit--make a template) about 3/4" from the top.
6. For a pot stand, try fashioning some apparatus with titanium wire that will sit over the lip.
From what I've read by those who have designed such stoves, that the size of the holes and their placement matters a lot for the performance of a particular sized stove. I don't know the formulas, but you could search www.repp.org's stove discussion list for assistance, or write to Tom Reed or Paul Anderson.
One could practice with tin cans to get the best setup, then transfer the dimensions to the expensive titanium. There are also many cheaper stainless steel double walled cups that could serve to practice on.
Just an idea--any takers?