Not to spoil the "corrector weight" party here, but the measurements supplied to me are in direct conflict with eachother. As a result I'm not convinced that the weight measurement is correct itself.
It wasn't measured with professional scales but even if it would be few percent off it still weights a lot and it doesn't change by using professional scales. I trust my scales more than your math based on these two and another mast that had smaller wall thickness, so there is too much unknown in it to draw any exact conclusions.
IMHO alu is only good to save some money (not even that much) when comparing to a carbon and building your own wooden one does that even better.
