Cantor

Score: 41.22 (pass)

ugly command line switching (and var names) for 2 extra points :-)

#!perl -li-
$^I.=$".$^I,$"x=3for 1..pop;print$^I

Score: 43.23 (pass)

shot # 2... also works under use warnings; use strict; but that would take too much characters :-)

#!perl -l
$a="-";$a.=$".$a,$"x=3for 1..pop;print$a

Score: 68.22 (pass)

First try, reasonably compact.....

#!perl -l
$_='-'x3**pop;s/(-+)\1\1/$1.(' 'x length$1).$1/eg while/--/;print