Comment by Pxtl

Depends on length and complexity, imho. If it's more than a line or two of procedure? Or involves anything counterintuitive? DRY at 2.

Extract a method or object if it's something that feels conceptually a "thing" even if it has only one use. Most tools to DRY your code also help by providing a bit of encapsulation that do a great job of tidying things up to force you to think about "should I be letting this out of domain stuff leak in here?"