OK, I'll play! But on condition that if I win, I get the title "Pernicious Enabler" that I've always wanted and deserved!
Anyway, I'm glad you did this: I'm rather a parvenu when it comes to TWAT, as my interest is really rather recent, and I have no "serious" luxury watches - a vintage Omega being the top of my meagre tree. But for that reason, I have a special interest in this price range: as a fellow mortal, it's one in which I can reasonably aspire.
So, here goes. Under $5k list is a difficult area, ruling out many of TWAT's more accessible staples - JLC MUT Moon or Reverso, for example. But the constraint brings in some interesting ones I think. What I've tried to do is find five that are inherently interesting and seem like good value, while at the same time are sufficiently distinct and different that if you were able, you might reasonably like to have all of them in your collection side by side.
In no particular order:
Chronoswiss Regulateur Automatic
An interesting modern brand with original designs. The "regulateur" is not a configuration you see on every wrist, and this has a perfect modern dress watch size at 38mm, combined with a retro style and just enough visual interest to be distinctive, while still subtle enough for true dress watch status. Comfortably under $5k, rave reviews and not at all run of the mill.
RGM 222 (921 Variant)
Roland G Murphy makes some lovely watches in my opinion. This one is so clean and simple while not looking at all derivative. I love the onion crown and the blued feuille hands. At $4500 it's well within budget for the entry level 921 version (the movement less decorated), and has the distinction of being that great rarity - an America in-house movement!
Nomos Zurich Blaugold
I have a bit of a thing for the German watches for some reason, and there were several contenders, but again I've pulled this out for its originality. Nomos are renowned for their Bauhaus-inspired simple designs, and this is no exception. But it's blue. Bluer than the bluest blue, in a way that just has to be seen in person. It's a big dress watch - 40mm if I recall, and with long lugs that will make it feel big. But an in-house movement, a strong yet super-clean design, and $4k price tag make it feel like a lot of goodness for the money. It's towards the top end of the Nomos price range, but I think it's a lot of watch. The black cordovan strap is not something you see often, either.
Cartier Tank Solo XL
Probably the most brilliant thing about this is that it's about $3k and yet it's a Cartier. I'd take the strap for the dress watch myself, and even then it's pretty big and bold. But in a good way. I don't think this one needs much further commentary - proper watchmaker, serious designer brand cred if that's your thing, and versatile enough for everything from jeans to evening dress I'd say. What more could you want, and the cheapest of the bunch too?
Rolex Oyster Perpetual 36mm, Steel Sunray Dial
And talking of brand cred, if that's your thing, a $5k Rolex. There is a school of thought, with which I sympathise, that all Rolexes are sports watches. The dress watches are called Cellini. But, assuming a strap on the previous model, I think there's room for a dress watch on a bracelet, and apart from that feature, there is nothing at all un-dressy about this watch. On the contrary, 99% of Rolexes are worn as dress watches at least some of the time, and as the most recognisable luxury watch brand, I think it had to be in here somewhere. I've always liked the simple no-date Oyster, and this new "sunray dial" version just launched is perfect. The one in all the PR pics is "grape" coloured, but this "steel sunray" finish is so subtle while unusual, that it's a clear winner for me. Old-fashioned 36mm size, muted colour, those simple stick markers and the masculine but clean oyster bracelet. Very discreet and classy. And it's a Rolex.