The 256MB appears to be a pricing error. Here's the deal, in the "In-Store Specials" flyer, the ad is for "LEXAR 128MB High Speed Series 12X CompactFlash Reg. $29 Now $14". Two stock numbers are listed, 2017-3152 and 2018-8761. The first matches the 128MB card while the other matches the 256MB card. Both are rated Lexar 12X.
$14 + tax is hot only in the sense that it is out the door without having the hassle of dealing with a rebate. Otherwise, you can regularly pick up 256MB CF at Buy.com for $10-$13 AR. I wouldn't get to excited about the 12X rating because it is primarily a marketing ploy by Lexar. Actual performance of the 12X is only marginally faster (at best) as regular CF in most digicams, even in digital SLR's.
One minor gripe, as stated earlier, the memory is in a folded cardboard held in a small blister window. It doesn't come with the usual plastic storage case.