The phrase "costly expert" is correct and usable in written English.
You can use it to describe someone who is experienced in their field, but whose services come at a high price. For example: "We hired a costly expert to help with our project, but they were able to make up for their expenses with the success of the project."
Defendants are entitled to often costly expert assistance, including the services of psychiatrists, as they prepare their cases.
Instead of experience and expertise being seen as an asset, it is implied that "costly" expert staff drain the resources of organisations, and solutions need to be found.
Capital cases are expensive because the trials tend to take longer, they typically require more lawyers and more costly expert witnesses, and they are far more likely to lead to multiple appeals.
The renovation took about five years to complete, which is not surprising when Jean and Steven explain that the painters alone spent thousands of hours on the project, most of them preparing the walls — which are, it must be said, almost impossibly smooth, with the depth of tone that only a costly, expert paint job can provide.
Pay-for-play and transparency reforms promised by the Treasurer have failed, year after year, to materialize — despite multiple costly expert reviews paid for by the pension.
She considered suing the doctor, but discovered she would need a costly expert medical evaluation.
But taking action against public sector workers can be costly, experts point out.
While a growing economy generates additional revenue, several of Mr. McCain's tax proposals would be costly, experts said.
Testing a suspicious powder for anthrax spores can be quick and inexpensive or slow and costly, experts said yesterday.
While the original program offered by Trump University had a price tag as high as thirty-five theusanext four years next four yeare arexpecteded to be far more costly, experts say.
B8 Tracking a Killer AN ARDUOUS TASK -- Testing a suspicious powder for anthrax spores can be quick and inexpensive or slow and costly, experts said.
