Mike:
It might not be evident from the photos, but the blade is almost 1cm thick at the base - it's nearly a cruciform. It's heavily built and robust - you have to hold one in hand to understand what i mean. In photos, they look puny and delicate. They are not delicate or small in person.
Also, FWIW, there is no technical reason a good bayonet can't be cast that are later machined and heat treated. Very few things are forged any longer. Typically they are either cast and machined, or machined from billet.
Materials science has come a long way since the 1960's. FWIW, every steel Ruger gun in existence is investment cast, machined, x-rayed, and then heat treated. I don't thing Rugers are known for critical failures attributable to their manufacturing process (high tech casting).
USA vs Chinese manufacturing, pretty wide gap there in QC lol.
The majority of Rugers are cast...the 1911 slides are forged, probably something learned from Para mistakes from the days they cast 1911 slides, and the Ruger American line is all forged steel as well. There were a pile of cast Ruger 1911 front sights that sheared off with very little use though.
And yes, I guess if it's just a pointy stick and not meant to double as a field knife it could be made out of aluminum or nylon for all that it matters...
I'd like to know if those $80 ones are chromed or just polished up. They look as close to the real deal as any so far.
Hammer that $30 one into a tree and see if it will hold your weight...that would be a neat test of it's durability... I may buy one just to see how hard it is to destroy it lol.