Your experience is abnormal. My statement is absolutely true, in all but some exceptional cases. CR123's are expensive. You want "cheap", buy AA's at Walgreens or Costco. There are compromises there, but in a pinch cheap is EASY with AA format, just about anywhere you go.
CR123's have never been "cheap". The best deal you can find for an "off" brand is a buck. I don't accept $1 each to be "cheap". Even web dealers with aggressive pricing get more than that for name brands. And if you have to get one tonight at Walmart, the price is more like $3-4 each.
Surefire gets $21 plus shipping for a box of 12 of their branded CR123, plus shipping. Surefire "broke" the pricing on these cells when they first made that offer. Back when I bought my 9P, they were way more.
You say comparing AA rechargeables to CR123 primaries is not reasonable? Hogwash! That's exactly what I DO recommend, and why I prefer AA format (as originally posed).
I prefer AA over CR123, and specifically, NiMH low self discharge AA's, and my assertion is that they are the better, less expensive choice, especially for anyone who plans to make regular use of a light with a high current drain.
The Sanyo Eneloop battery has made small high current portable power a new game, and one that CR123 format doesn't play nearly as well.