A scutch chisel will last longer than a regular chisel as it does not need to be constantly resharpened. This is due to it having replaceable cutting edges in the form of the scutch combs and droves.
This means you will not need to buy a new scutch chisel as often as a regular chisel.
A scutch comb/drove is cheaper to replace every time it becomes blunt in comparison to paying for the regular chisel to be resharpened and eventually replaced when it becomes too blunt.