According to the Washington Naval Treaty of 1922, destroyers were limited to 10,000 tons. The Z comes in at 14,000. The Type 055 comes in at the limit of 10,000 tons.
Cost of the Z $7.5 billion
Cost of Type 055 $750 million
So, the question should be is the Z better than ten Type 055s.
The Zumwalt is a technology testbed, so the cost comparison isn’t really apples-to-apples. A better comparison would be with the Arleigh Burke class.
A better question would be, would a Zumwalt class ship be able to triumph in a ten (or greater) to one confrontation against the type 055?