Where is the significant point of diminishing returns on hi-end turntable?


For those that don’t know me I am newish to this game. Yes, I believe this chase for perfection in sound reproduction is a game. There are endless variables affecting the sound of every system and 100x that in opinions on each of these variables. I love cool $hit as much as the next guy but I am looking for an analog rig and I keep getting drawn into the seemingly endless "what about this option that costs tons more?". I started with a $6 to $10K budget and now I am considering a $25K setup (Table, cart and phono stage) after talking to a local retailer. I will be blunt, I want to be that guy in the Memorex ad from the 80’s that is getting blown away by his system (my impression is he is overwhelmed by the amazing sound coming from that speaker not the volume). Now that I have acquired some pretty descent stuff I am spending 15 plus hours each week listening and really enjoying this hobby. I don’t want to have any regrets and just be marginally satisfied with my setup but where do I draw the line? Back to my initial question; what is a reasonable amount to spend on an analog setup to achieve the best bang for the buck? I may be somewhat unique in that I don’t want to constantly be upgrading my equipment, I just want to buy great products the first time that are very satisfying and spend hours listening to great music. I don’t want to be the guy always chasing the next great thing.
128x128mmporsche
"   I can understand how to do everything but that doesn't mean I am going to do it ".

Exactly. This is not American frontier three hundred years ago. Besides, I think we should support each other as professionals if possible. But, there is one thing that I will always do myself even if I am not in the mood and that's sharpening a knife. I was taught the basics and then spent hundreds of hours to perfect the technique. Yes, I can always send my custom knives to the makers who will sharpen them for free, but not better than I can, faster but not better. You do it by ear and by touch - any knife, any original angle, no guessing.
Mmporsche, you should enjoy playing reel to reel deck, including music recorded from your favourite record albums. Decks are great, you just have them serviced from time to time and clean the heads every, say, twenty five hours, and that's about it.
Some others might disagree but I wouldn't rush to spend thousands on isolation platform and footers. I mean Vibroplane, K-Minus, SRA custom, top of the line Stillpoints. Any of them might be the best solution for your particulat table  but not nesessarily so, besides, they are quite expensive. It's not possible to know what would work best without experimenting. You could ask the table manufacturer for the advice, in addition to your " local experts ". Many just use thick maple platform with good brass cones under it or Symposium platform with rollerblocks. Neither is the best, I suppose, but may be close enough depending on the table and hearing abilities. With my modest set-up I can't hear the difference between 2" and 3" thick maple platform under my table, I keep 3" one though because my table is on the floor and the 3" is much heavier and sturdier.
Where is the significant point of diminishing returns on hi-end turntable?
From my experience the significant point of diminishing returns on a hi-end ’table begins after attaining a consistently high degree of speed accuracy.

Necessary conditions include clean records, a level table/platter, a top-notch alignment and optimal VTF. Get those five things right and you’re off to a good start.

A budget of $30k for 'table and 'arm should give you enough headroom to investigate alternatives that will cause a minimum of mechanical headaches and last for many years.

inna, "... I wouldn't rush to spend thousands on isolation platform and footers. I mean Vibroplane, K-Minus ..."

Given the amount the OP in spending on the system, and analog front end, the cost for a Vibraplane or Minus K is not that significant. Not having one of those under a turntable at that level is an oversight. 
mmporsche - I am seeking out the local experts and will have them setup my table.  If I need to adjust something than I will certainly have the knowledge and tools.

Local experts – implying someone that will get you to about 8-9 out of 10 on the first setup. Local experts have familiarity with certain brands.
based on the info you have provided on this thread, one of your objectives is "set and forget"

If this was me, I would be looking to get real life experience, opinions, from actual owners here, on those table setups/ brands that the local experts represent and are promoting. I would be listing out the brands.
Otherwise, you will continue to get new TT candidates here from members.

Good luck in your hunt.