Collocations for overestimate - verb

considerably, greatly, grossly, seriously, vastly
consistently
The department consistently overestimated its budget deficits.

tend to
be easy to
It is easy to overestimate the cost of this kind of research.

be difficult to, be hard to

by
We overestimated the cost by about 2%.

sth cannot be overestimated
The importance of this group cannot be overestimated.

Overestimate is used with these nouns as the object:
ability, effect, extent, importance, size, value