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
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. 
It would help if the OP would identify his current TT and also describe why he is not satisfied with the Parasound phono preamp.