Do I buy an upscale TT?

I would expect anybody who is introduced to a System for the first time, in a home environment, where the system has been carefully put together to get the best from the sources selected to be used, will be impressed with the demonstration offered.

It does not take a $50K TT to seriously impress in such a set up, a lesser valued TT, can I am sure offer a great performance.

I in the past and mainly prior to covid times, had travelled a Four Hundred Mile round trip to attend a HiFi Clubs periodical event, where the meeting place has a resident £200 000+ system.

The Speakers and Amplification alone retail at £140K.

The loom is said to be near £20K. 

The main attraction is to get to hear devices brought by others slotted into the system, to see how they perform in such Hi End Company.

Vinyl and Speakers are the biggy, with Digital being the less frequent.

I have heard modified TT's and Tonearms costing a £1000 as donors prior to being modified, hold their own alongside TT > Tonearm > Cart's costing 20-30 time more as a retail price.

No Different with Phonostages, the resident Phon' is a £10K retail price, and it isknown this model quite happily competes with Phon's upto twice its value.

I have witnessed the resident Phon' matched with the homebuilt Phon' Designs, or  even bettered, if a certain range of a frequency is ones most preferred. The home built designs costing approx' £1500 - 2K, produced by adept EE's, can really shine out for the attractiveness they offer.

I have also heard these home produced Phon's make Commercial products sound very inferior regularly, that are 2.5-4 times the price.

As advice for the OP, I would suggest continuance of enjoying the system that has been produced.

Whilst enjoying what is already in place, I would suggest attempting to experience other systems, whether personal owned or from a commercial environment.

There are experiences to be had that can be of equal impression to the friends system, and possibly achievable for substantially less monies, if wanted to be pursued.

Keep a open mind, Branded Items are produced with tight financial constraints, and can quite easily be placed in the more expensive end of the market, especially if aesthetic appearance has been the heaviest of impact on the overhead to produce.

The DIY Market is not so constrained and a lot can be offered for not too much, the end aesthetic might be a little robust but 'hey ho', it is easily overlooked if one does not do their listening with their eyes. Bear in mind the TT's you are focusing on are coming from this background, and is possibly evolved into a cottage industry, with a High Mark Up on a product, due to a small turnover of sales.   

I sort of chuckle when I read some of the stratospheric cost figures that got tossed out here for sound reproduction systems. Personally, I'd take that same "budget" and attend more *live* music events, where the sound is, well, the sound you're trying to replicate in your room. I'm fortunate enough to live in an area that supports a wide range of live musical performances, so I get my fill of classical, jazz, and rock performances--these are my true "reference" system.

OP  if you have the money go for it.

Since this system is owned by a friend I assume that he would help you analyze this opportunity to upgrade. Do you and your friend both have CD players hooked up to your systems? If so you can start with a simple comparison that will answer a lot of questions. Note: When I say Turntable I mean the entire system including tonearm and cartridge.

Pick a vinyl record and the corresponding CD title from your collection that is good demo material. If you lack either the CD or the record, buy it. Compare the CD and the vinyl on your system and note the differences - frequency response, detail, soundstaging, etc. Take the CD and vinyl to your friend's house and do the same. Does his TT blow away the CD? What are the differences there? Does the CD sound amazing too?

This test can be valuable for a couple of reasons: 1) CD players are much more uniform in SQ than turntables so they can provide a good reference, and 2) If you hear substantial differences between your friend's TT and CD player it will help you analyze what you are hearing and what appeals to you.

This is easier than @tomic601 's suggestion of lugging your TT to your friend's house but I heartily endorse his idea too. Before you contemplate spending tens of thousands of dollars it would make sense to do some due diligence. Besides, geeking out with your audio buddy is a great way to spend an afternoon.

Hipsterjefe If you can have both , expensive system and able to go to live music why not? Here in Illinois I live close to Ravinia festival.and 30 minutes from Genesse theater where they have good line up of musicians. So I ussually attend live music as well. I hope I can attend where Patricia Barber plays with her band in Chicago, I live 30 minutes from Chicago as well.