It's the same in Spanish. "Cuanto sale esto?" Basically saying "how much does this COME OUT to?"
I wrote "how much does this go for" and got it wrong, but it seems to be the best translation to this kind of expression, since "sair" is used, no?
Some kind of "what will be the retult?".
If we look first to "quanto dá isto?", which means the same, maybe it's easier to understand.
When you do calculations, it "gives" or "brings out" a result. "Dá um resultado", or "sai um resultado".
sai??? is that word okay in this sentence? Why not: Quanto é isto? Or: Quanto isso custa?
Hmmm... not easy to answer... "Quanto custa?" is as common as "Quanto sai?"
So do this mean "how much is this" IN VOLUME not cost? Versus "how much is this?" IN COST - QUANTO CUSTA ?
"Quanto sai (isto)?" is about cost, not volume. "Quanto é?" can be used for both cost and volume?
So you can say either "quanto sai" or "quanto custa" ? Which is more common? Thank you!