Here's my own "Nice Luxman Find" story.
It is now 2014, 6 years later than previous posts, and I found the same models - 5C50, 5T10 (I prefer analog tuners anyway), and 5M21 - on ebay from two different sellers for just $1500 total, including shipping. (The amp seller also had the same model preamp and tuner listed, but I actually saved about $500 by not getting them from the same seller.)
All three pieces in near-new/mint condition, in original boxes etc!
It should all be here within a week or so, and I can't wait!
I already have a K12 deck from before, but it needs to get serviced. It either needs some general help/TLC, possibly new belt(s), or it might have been changed to 240v inside and I can't be sure. It doesn't seem to "light up enough" on 120v, but if I try it on 240v and I'm wrong... well, POOF!
Actually I already have TWO K-15 decks also, including one which is also in the original box with manual etc. But with the rosewood cabinets of the K-15s, the K-12 is probably a better match for the LRS components, appearance-wise.
I don't expect to ever get a LRS 5K50 deck (actually there is one on ebay now, but despite all its flaws and problems the seller still wants almost $2,000 for it! I'm not THAT crazy! I paid around $60 for the in-box K-15!) If I can find a K-10 that's just in the metal cabinet, the K-10 looks closer to the 5K50. But for now I can get the K-12 serviced, or just use the best of the K-15 units that I have.
And in the meantime as I wait for the Luxmans to arrive, I listen to my "everyday" setup, Mitsubishi DA-C20 tuner/preamp, and DA-A7DC power amp with DA-M10 meters front, driving Polk Audio Series II Monitor 5jr speakers and Polk powered subwoofer.
Oh, how I suffer.
On top of the cabinet with the Mitsubishi gear, I have a Luxman R-1500 receiver on display that I also got in the original box, for under $100, several years ago. Not currently connected to speakers because it gets too warm when played at levels that I enjoy. But it's too pretty to be out of sight. It's a 240v model but that doesn't bother me since all my computer gear runs from 240v anyway. So I just run an extension cord from there.
And upstairs in "storage" I have a Luxman 1050 receiver that didn't fare well in shipping to me. It had been in mint condition but the seller didn't pack it very well, and during shipping the big tuning knob came off and rattled around inside the box inflicting scratches. Such a pity. I want to get another sometime, still pristine and shipped to stay that way; or perhaps the 1070.
Oh, didn't the HH Scott digital tuner come out before the 5T50? I'm also a big Scott fan, they pretty much invented hi-fi especially FM, and they should get the credit they deserve.