Another option to reduce the stat() calls would be to call it once at the beginning of the loop, saving the results in an array, and then referencing the array after that. Alternatively, call it once with the filename as the argument, and then for the rest of the loop replace the filename with the special filehandle "_" (underscore), which checks the cached results of the latest stat call. See stat for more info.

Personally, on any system with unix-ish tools available, I'd move most of this into a find command, then use xargs to pass the list of only the files to be deleted/archived/whatever to a script which would do that.