if we take PHB numbers, I'm just trying to give a picture how a container might look like, be it from steel or glass.
Sure, number are gamist, but we can still run those numbers and say are those reasonable or not.
personally, it's a bit too much. 1/4lb would be more appropriate, but as I said, adventurers life is hard and dangerous, so they might want to over engineer the container to survive combat abuse.
on the other hand, acid vial needs to break on purpose so that glass should be thinner.
I always envisioned part of the cost (and weight) being special containers if I thought about it. Acid flasks are extra heavy because they act like grenades - inert and hard to break while carrying but pull a pin and the protective container has to be negated somehow.
But I still think the best solution is something like