The BOGO isn't free, it's included in the price you pay, as is the Grab Bag item. It's not icing on the cake, you're paying for it. I suppose it depends if you believe the price quoted on a product page is actually the unit price of the item. The constant sales, coupons, BOGOs, vouchers, discounts and whatnot are all costed in: a handful of people will buy at quoted price, a whole lot more will buy at some sort of discount. The genuine unit price is much lower than the one you see on the product page. That's Renderosity's business model, and it's the same at Daz. You calculate how many widgets you need to sell at what price in order to make a profit. And you certainly don't reveal that calculation to the customer. Consumer capitalism 101.

Nor is it simply that the grab bag didn't appeal. It was one I can't use. Renderosity had included a product that they know a large part of their customer base can't use: they know better than to assume that everyone here uses Poser. That's been the case for years, as they well know. But the product page for the grab bag item I got says 'This product does not work in Daz Studio'. Putting that into the grab bag mix is thoughtless at best. I'll be grateful when I get professional customer service: someone who says, "Let's try to solve this problem," rather than "We'll maybe think about it some other time."
Like I said before, this isn't the village fair. It's a business transaction and the normal rules of business apply. Good service gets my loyalty, my word of mouth, and my money. Bad service just gets my word of mouth. So far, this has fallen way below any standard of good service.