Retail is for the guys making living with their tools and time is money.
Used is for the rest of us. I've got more tools than most working techs, but every one of them was bought used at garage sales, estate sales and craigslist.
As much as I love the GJ classifieds, with all the tool sharks here, you won't find many bargains. Use the GJ classifieds to find the upper limit of what a used tool is worth and then you'll recognize a bargain when you find it locally.
Even though most of my tools are Snap-on, the bargains will probably be Wright, S-K, Williams, Bonney, Easco, New Britain, Proto or Craftsman Pro. Any of these are more than good enough for professional use.
jack vines