I guess the term "high end" would have to be defined in some way that all of us could agree on it first. Someone may think high ends is anything over $200, another might think something over $300, someone might say only $500+ and there are a few that may think only high end if it is rare, collectable, limited run, special color plus some sort of magical price point.
Personally I think anything under $50 is pretty much a disposable reel in the same sense someone would buy a disposable razor to shave with. Just something to use to get by but thinking is not precision or long term with all the plastic in the construction. Around $100 and you are in everyone's favorite price point for the budget stuff. Usually the reels are built much better and things are significantly noticeable from the $50ish reels. Jump to $200 and you are getting into the good stuff. Sort of like the Honda Accords and Toyota Camrys. You get the reliability, quality construction and a few more bells and whistles. Jump to $300 and you usually are starting to see things like special spools, magnesium frames, higher quality bearings, sometimes longer or CF handles. Clear the $300 mark and the improvements are less noticeable. Usually a bit lighter, sometimes a more sophisticated breaking system, perhaps a fancy paint job. When you get into the rare reels you are mainly paying for the collectability and condition of it. Some things were only produced for a year or two, some came with collectors pins, some are nearly impossibly to find used in about any condition nowadays.
I wouldn't want to be the one to tell you what you should buy. However I do thing something JDM would be a good place to start. The one thing people don't always realize is that by buying a JDM version of a reel it can only be less expensive. Take the US Metanium MGL vs the JDM Metanium MGL.
The other thing I would ask myself is what do I truly want my high end reel to do that my current reels don't? Do I want it to be lighter? Do I want it to be a reel known to be able to cast for distance? Am I wanting something that many would consider as smooth as a baby's bottom? Am I wanting something rare or limited?
Here are 4 $300 retail Shimano reels that I currently own and use and a brief run down on them
1. Chronarch D7 - It casts easily with minimal effort, when you really get on it the casting distance is very incredible yet controlled, and when you reel any bait or are reeling a fish in it is just as smooth under load as it is without.
2. Core 50mg7 - This reel is pretty tiny and compact yet the magnesium frame feels super solid. It casts everything great from lighter plastics and jigs to jerkbaits and small/medium cranks.
3. Metanium MGL - The breaking system is incredible and casting distance is as good as you can imagine and as good as your thumb will allow. The external adjustment really helps fine tune it more than the Curado I IMO.
4. Exscence DC (older model) - Pretty much the wow factor Masterbait'r was talking about. Yes DC reels are a bit heavier due to the digital system they utilize. This reel is super powerful and super smooth and the casting distance is as good as any of the other reels I listed above maybe a touch more. One cool thing about the reel is the clicking drag. No, I am not talking about the drag start clicking which it does but rather when a fish of decent size pulls drag you will here it click. The other cool feature about the reel is the night mode setting? Ever been fishing before when it was so dark you couldn't see when your bait was going to touch down? Well with this setting you can cast 100% without your thumb and not have to worry about one small over run of line. Perfect for a new angler starting out or a kid that is getting started.
I am sure more could be written and said. Is it worth it? Who knows as that is up to you and everyone else to decide. It would be hard to sit here and tell you something higher end will help you become a better angler, catch more fish, or be something that you can feel and see the "difference" in. At the same time there is always those folks that go cheap on everything, even when they can afford yet are always having equipment related problems.
Best advice with whatever you piece you decide to buy is to one shop around whether buying new or used. And also make certain you keep the reel in a reel cover when not in use should you decide you don't like it you can sell it for a much smaller loss than if you use it and it takes a beating on the exterior. For example I have seen mint Chronarch D reels go for $300ish in near mint condition while reels with marks, scratches, and dings sell for around $200. Talking $100 difference due to the exterior condition of the reel. Also keep your reel, box, papers, and add'l items that may have came with the reel as they will only add to the value and appeal to more buyers as well.
Hopefully that helps. Sorry for the ramblings...