I bought my first set at Radar Electric back when they had a store front for small orders. They've since changed to commercial orders only, so the last set I bought were from ebay. They are exactly the same as the first set AFAIK but cost significantly less. The first set cost $10 for 2 50 packs (plus tax). The set off ebay was ~$3 shipped for the same quantity.
Keep in mind, these are not insulated, so Randy's are definitely nicer in that respect!