Seller is asking $1350 and claims they work perfectly. The price feels high to me.
New LaScalas ordered from Klipsch are $3500
each. Yeah, they're expensive, used ones go for premium prices, too.
I have the plans to make the cabinets for the LaScala, Klipschorn plans are floating around the web. The LaScala plans are pretty simple, but when you get into the compression drivers, horns, and "balance" networks (what Klipsch calls a crossover) the cost mounts. DIY KHorn plans are more complex, the waveguides in the cabinets will require more skill to cut and assemble. All in all, you can build your own based on Klipsch design for half the cost.
I'd like to try...
BUT: Horn loaded drivers can tend to be a bit directional, the sound may change as you move about the room. A few of the crossovers have attenuators built in to adjust for brightness of sound, but not the directional nature of the horns. Horn loaded squawkers and tweeters (Klipsch calls the midrange drivers "squawkers") can also tend to be a bit on the bright side. The woofers in themselves can also require that you put your speaker systems in the corners of a room, the corners being an extension of the horn loaded woofer. LaScala is less picky on placement.
BENEFIT: Higher efficiency! You can get more volume per watt with horn loaded systems. I've never heard a pair of Klipsch, but I've also never heard of anyone complaining about the sound they produce- it seems that the people who have them like them.