Last month, I got my cellphone bill and it cost too much.
Does the highlighted part make sense and sound natural in English?
Last month, I got my cellphone bill and it cost too much.
Does the highlighted part make sense and sound natural in English?
X cost(s) y means X has a price of Y. When used in the past tense, it can mean that Y was already spent and you now have X, and it can also just mean X had a price of Y in the past.
It may seem odd to use cost to refer to things that vary month to month, such as bills, but this is OK, people say this all the time.
But without modals or time expressions it does imply you already paid your bill, so saying "Next month's bill cost too much" is bad, but "Next month's bill will cost too much" is OK.