At an excessive level (3-4)
I believe the answer is:
sky-high
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">at an excessive level</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sky-high that I've seen before include "Very elevated" , "At an excessive level" , "Very pricey!" , "such costs are very steep" , "At great altitude" .)