Updating my preamp.Frustrating..You Bet

In your price range, you could easily get a CAT SL1 mkIII. I auditioned about a half dozen preamps and the CAT was my favorite. It's reputation is well deserved. It is not excessively tube-y or overly dry, it's built like a tank, and really has no sonic signature except that it's not solid state. It sounds right for all types of music - and I listen to them all: classical, rock, jazz, electronic, ethnic, funk, blues, R&B etc. Plus, they hold their value well and the company is very responsive if you have issues...

for less than $2k you could find a rogue audio 99 magnum tube preamp either used or a dealer demo. call rogue and speak to mark o'brien. he is honest, reliable, trustworthy and will help you in your decision making process. his tube amps are downright bargains in the hifi world and deliver incredible value. mark is the type of guy that will tell you NOT to buy one of his amps if he feels it will not serve your needs. he is a pleasure to talk to and has gone WAY out of his way to satisfy his customers. for example, my 99 magnum was purchased through audio connection of verona, nj as a dealer demo. ups delivered the preamp after dropping it and smashing a corner of the sweet aluminum faceplate. i contacted mark who proceeded to file a complaint on my behalf with ups. within 2 weeks i had a new faceplate sent to me at no charge whatsoever. btw, replacement plates run about $80 from rogue. if you don't know, rogue offers stock and magnum models of all their amps, the magnums being outfitted with better caps, resistors, tubes, etc the stock amps are good, the magnums are at another level altogether and i would advise this route. however, stock amps can be factory modified to magnum status anytime you want.
my personal experience with the rogue 99 mag has been heavenly. the soundstaging is immense and the amp is pleasantly transparent. i will not bore you with more adjectives and anecdotes, the rogue amps need to be heard within your context. i'm confident the 99 will not be a letdown but rather a revelation at just how much you can get for uner $2k.

I'm very happy with my Atma-Sphere MP-3. The line stage is under 4K, more if you want to add phono (great phono stage, btw). It does run only balanced outputs although that can be adapted.

Yes, it can be Frustrating ( choosing ).
Thats a Great price range for a TOP tube PreAmp, you should be able to pick up a Very Good 1( here on audiogon ) - and it should make quite a Big difference ( I've tried many others )! Too bad you can't audition some on Your system.
Presently using a Balanced Audio Technology (BAT) VK-5i ( I bought on Audiogon for $1885.00 about 1 year ago )and just love it. The Sound of my VK-5i is Incredible, can't imagine it getting any better. But it will once I upgrade!
I am ( in a few months ) going to upgrade it to VK-50SE Status. The VK-50SE is considered 1 of the BEST Tube PreAmps ever made ( Class A - World Class ALL the Way). I have Not heard a Better Sounding ( or seen a better built ) Preamp. You can probably pickup 1 on Audiogon at a good price. Good luck.

Speaking of PreAmps, you might want to look into the Hovland, a great tubed pre, that you could most certainly buy here on Audiogon. It doesn't, however, have a remote. Other PreAmps of note are the Herron, Joule Electra's LA-100 and, of course, Cary (the 98 or the 2002). All of which, I believe, fall within your price range and sound very nice indeed. I would agree, that being able to listen before you buy is highly recommended.
Good Fun!