"The cost is especially high."

"Especially" means "more than usual or expected." It is used to emphasize that something is particularly or exceptionally the case.

Here are some example sentences using this phrase:

"I was surprised by how expensive the tickets were, especially since we bought them last minute." (Translation: 我很惊讶机票的价格有多高，尤其是我们是在最后一刻买的。)
"The price of the car was especially high, so we decided to look for something else." (Translation: 这辆车的价格特别高，所以我们决定寻找其他车。)
"I thought the hotel would be cheaper, but it turned out to be especially expensive." (Translation: 我以为酒店会便宜一些，但事实证明它特别贵。)