Format number in $x.xx format using Perl

In my CBC design, I'm pulling prices from a question outside the CBC and then multiplying times a set of constants. My code (which works) is:
$[%

Begin Unverified Perl

GETVALUE("Q2b") * 0.65;

End Unverified

%]

The problem is that depending on the value in Q2b, it sometimes shows up with 1 place after the decimal, sometimes with two, sometimes with none.

So, I'm trying to figure out how to modify the Perl script to always show 2 decimal places.

Thanks.