If you want to do a little assembly work, consider the Linkwitz Orion3. You can order the drivers, prebuilt crossover, prebuilt cables, and prebuilt cabinets for just about $5,000. No cabinet building or soldering necessary, you just have to assemble it, Ikea-style. You'll need to spend another $1,000-$2,000 for amplification - they need eight channels around 60W each. Arguably, it's the best speaker at any price. I have the drivers, all the parts, and two suitable Adcom amps. I'm just waiting to get my shop together to build the cabinets. We thought we'd have the shop ready last November.
Maybe this November.
Also put Quad in the running. The ESL-57 is a classic and sometimes gets voted as the best speaker ever. I've never heard better mids, period. However, I think the ESL-63 has better overall balance, so I bought a pair. Highly recommended. If I had known how good they were a few years back, I would have just bought a pair and stopped chasing the audio dragon. The ESL-988 and ESL-989 come in under $10k, too, and are similar to the ESL-63. A pair of Quad ESLs has been the end of the road for many audiophiles.
I'd also put in the running the big pairs of Magnepans with ribbons: the 2.5, 2.6, 3.6, 3.7, and 20. You can get all of them used for under $10k. If you have the room and sufficient amps, the 20 is stunning. Though I'd look for a used 2.5 around $1,000-$2,000. You get a real ribbon and a nice bass panel. Ribbons are really special - I never would have gotten into high-end audio if it weren't for the Verhagen ribbons I built. They knocked me flat.
A dark horse might be an AMT speaker. I found ESS AMT-1 speakers a few years back and am still deeply impressed by the AMT. However, the woofers are what you'd expect from a 1972 design. I replaced them with modern woofers (about $160 for the pair) and they're surprisingly good. Not as coherent as the Quads, but awfully, awfully good. There is a modern AMT being produced called the Kithara that runs around $6k. I haven't heard it, but if it integrates an AMT with a dynamic woofer well, it'd be formidable.
For speakers I haven't heard, a lot of credible people love the Vandersteen 5. Worth considering. So are Lowthers - they have a rabid cult following. And while I only heard Klipschhorns a good 20 years ago, before I got deeply into audio, they still hold a certain fascination for me. Take a look.
