Just out of interest, how much did it cost?
我只是好奇问问，这个花了你多少钱？
How much will it cost, more or less?
这个大概得花多少钱？
The total cost to you is 3 000.
你总共要支付3000英镑。
How much does it cost to become a member?
要成为会员得花多少钱？
It's time we got on to the question of costs.
我们该讨论成本问题了。