i'm abandoning Zona in favor of True Temper tubing for the time being, probably Versus Heat Treated. Jury's still out on Reynolds, though.
these figures don't include shipping and other such costs, but even so, they're revealing.
i'm assuming 2 tubes of 28.6mm diameter and 1 of 31.7mm, all .8/.5/.8 mm thicknesses.
Zona is $54.72 from Nova, yields at 137,785 psi (950 MPa), so $0.000397 per pound per square inch.
True Temper VHT is $43.85 from Henry James, yields at 175,000 psi, so $0.000250 per pound per square inch.
True Temper OX Platinum is $81.60 from Henry James, yields at 185,000 psi, so $0.000441 per pound per square inch.
VHT is thus the best value according to my numbers, by a pretty good margin. Zona's the weakest, but not the cheapest, so what's the point?
these numbers DON'T take into account weight, but i'm not a weight freak.
if a tube suffers a big hit, nothing matters except the strength of that tube...a broken tube isn't worth anything to anybody.
i imagine the strength increase from 175k to 185k must take a lot of work, or else True Temper wouldn't charge nearly twice as much for it.