I have used Balsa USA for building supplies for fixed wing aircraft for more years than I care to mention. I checked their website and they carry materials to build a wooden frame H-quad.
1 ea. 1/8 x 6 x 24 Poplar Lite Plywood $2.06
4 ea. 1/2 x 1/2 x 24 Basswood Stick $1.17
The lite ply is tough stuff. We have been building giant scale fuselages with it and when properly braced has no flex at all. For less than 10 bucks you’ve got yourself a frame.
Running through some quick calculations, the Flitetest frame should weigh between 200 and 245 grams depending on dimensions. That's roughly 1/2 lb. for you Imperialists.