Why should closures be cheaper in this situation?

Its the difference between having one function and many. The closures can all use the same compiled code internally; only a copy of the lexical environment needs to be kept. Generating accessors by eval'ing them into existence, the strategy used by Class::Struct as revealed by PodMaster, results in newly compiled code for each one.

-sauoq
"My two cents aren't worth a dime.";