that's not really true

You need:
prepare material,
1 month Ad,
1 month wait,
then file PERM, usually approved within a week.
total 2.5 month.
As for preparing the material, one week is more than enough(i.e., you carefully review the material and discuss with the lawyer). In my case, my lawyer basically throw me a copy and said "this is the best and gaurantees eb2", and everything else are already in his office since he also handles the h1 application.