Best tube pre-amp below US $ 10.000,00 ?

Frankpiet I sure it's in the same "league" but I've never heard any of them in a direct A/B comparison with my gear which in the ONLY way to know; the bottom line is, it depends on what YOU like. Don't be concerned with reviews and retailers where agendas abound. I've owned ARC, CJ, Dayton Wright, Pass, Harmon Kardon, Dynaco, and Aesthetix preamps over the last 40 years. The Grange is my favorite and more than likely my last preamp.
With regards to Grange/Cortese, again I've never heard an A/B comparison. However there are quite a few Cortese owners here on Audiogon with sophisticated systems who love it. IMO (and this may start a ruckus here) it's difficult to purchase more for your money when you buy a Supratek. There is no retail intermediary adding 40%-50% to the purchase price. Lastly, there are very few used Suprateks on Audiogon. Why? Owners tend to keep them. If you happen to see one posted it generally sells very quickly.
ALL OF THE ABOVE IMO

Sounds_real_audio
Let me get this straight. If somebody buys a deHavilland from you they are a good customer. Conversely, if a deHavilland does not suit their liking or system they have a "tin ear". Take me off of your prospect list and keep the bacon frying.

time to put the brats on the grill.

Isn't that illegal? I usually just take the car away for a couple days.

Supratek. Hand built, point to point, and gorgeous. The phono stage in my Supratek absolutely murders my previous phono stage, Aesthetix Rhea, no contest. Downside is you'll wait at least 3 and up to 6 months. That being said, I'm glad I waited.

Franpiet
I dunno. The only way to determine that is to audition each of them in your system. Hearing them side by side by side at a dealer would be helpful provided the amplification and speakers were similiar (ideally identical) to your own. However the chance that any retailer has both Hovland and CAT is small although you may find one in larger metropolitan areas. Supratek does not do retail so a 3 way comparison is quite unlikely.
Performance vs. $$$ I think Supratek is untouchable as you are saving 40%-50% buying owner direct. All of course IMO.
FYI, I have the Grange not the Cortese.

You know if you guys moved to Massachusetts, everything would be much simpler.