At a low cost (2,3,5)
I believe the answer is:
on the cheap
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">at a low cost</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 on the cheap that I've seen before include "At a low cost" , "Inexpensively (sl.)" , "with minimal cost" , "(Done) inexpensively" , "By cutting a corner (on expense)" .)