1. Is this one on sale?
這個打折嗎？
還能這樣說：
Is there any discount of this one?
Any discount?
諺語：
One boy is a boy; two boys half a boy; three boys no boy.
一個和尚挑水喝，兩個和尚抬水喝，三個和尚沒水喝。
2. How much is it on sale?
打幾折？
還能這樣說：
What's the discount rate?
How much discount do you give?
諺語：
Much will have more.
越有越貪。
3. How much is it?
這個多少錢？
還能這樣說：
How much does it cost?
What's the price of it?
應用解析：
make a price 開價，定價；
cheat at the price 物超所值
4. How much does it come to?
總共多少錢？
還能這樣說：
What's the total?
How much will it be all together?
應用解析：
come to 還有其他意思：蘇醒；結果是；涉及，談到。
例如：She came to herself after being knocked down.
她在被撞倒之后蘇醒過來了。