I'm not sure I would agree with this (throwing a bone in here to start another discussion). While I agree that one of the purposes of developing a program is to create it as lazily/quickly, readable/maintable as possible, a bigger purpose is to serve the end user of the program. While we're talking about microseconds, they can add up under exponential usage (such as IMDB using mod_perl instead of CGI scripts) and if the user can appreciate faster response times, I'm for taking more development time and serving that purpose.
My argument only holds up in those special cases, though, where the usage is enormous - so I'd answer the original pos(t)er of the question with "It Depends" (the quintessential answer of Consultants everywhere ;)) and it depends on the usage of the program.
And if you're talking about a totally different dev environment (C, Assembly, etc), where I'm not proficient in and would take significant research/dev to get proficient, Perl's good 'nuf for me (so that would be another exception to my argument ;)).