Those bars on Ebay just... don't... look... right? Maybe it's just the photos, but as Mike pointed out, the drops look perilously deeper than any original Dirt Drops I've ever owned or seen. Also, all were sleeved, not bulged a la the auction.
Not sure if you've ridden on Cunningham-era bars and attendant variations, but short of the Specialized BB-1, you might find the tops a bit too narrow for CX, esp. if you plan to run interruptor levers. Just my two bits.
(Those Nitto RM-013s are a readily available compromise if you're after both flare and tops.)
Jeff Hagedorn
Warragul, VIC Australia