Why English speakers try to squeeze *does* into *¿cuánto cuesta?*

English asks "how much does it cost?", with a helper verb doing invisible work. So English speakers instinctively hunt for that "does" in Spanish and try to pad the question. There's nothing to pad: it's simply ¿cuánto cuesta? — "how much costs?" Spanish has no equivalent of the English "does", and adding one only breaks the sentence.

Prices bring two more small English habits. First, we say "one hundred and one"; Spanish inserts no "and": ciento uno, straight through. Second, quantities keep their de: "a kilo of apples" is un kilo de manzanas, never un kilo manzanas. That little de means "of" and can't be dropped the way English sometimes swallows it.

• ¿Cuánto cuesta? — How much is it?
• Ciento uno. — a hundred and one (no "and").
• Un kilo de manzanas, por favor.

Picture Don Beto at his market stall: you point, you ask ¿cuánto cuesta?, he answers with a clean number, and you ask for un kilo de whatever you fancy.

Say it with me: ¿Cuánto cuesta? Un kilo de manzanas. No helper verb, no extra "and", and never drop that de.