Getting awk in your head (fully) takes about an afternoon: reading the (small and exhaustive) man page, going through a few examples, trying to build a few toys with it. Perl requires much, much more effort.
another commenter said something similar - But nothing says you have to learn everything - you can learn a subset of perl that does everything you would want to do (with awk), would that take as long?
Yup, but defining that subset isn't free! Perhaps some people did the work already, but I'd still be cautious as to how much Perl one actually need to know to use those comfortably.
Getting awk in your head (fully) takes about an afternoon: reading the (small and exhaustive) man page, going through a few examples, trying to build a few toys with it. Perl requires much, much more effort.
Great gain/investment ratio.