Cost benefit analysis is hard...
My system has a 25 year old turntable and a very heavily tweaked pre amp and power amp. The pre amp in particular bears no relation to what it was as it has a different power supply and loads of Shinkoh and Caddock resistors as well as different caps. I spent a lot on it.
The speakers are what, 15 years old?
My point is that my system probably counts as mostly vintage not "up to date".
But am I happy with my system? Pretty much yes. Is it an assault on the state of the art? Hell no.
Cost benefit: The problem is that how I would score it varies from day to day... Most of the time I would score harshly & say its a 7/10 on my arbitrary scale. Last night, playing James Brown on the right pressing at the right volume with the lights off and the system warmed up*, it was a 9.75. U n b e l i e v a b l y good. Tomorrow WILL be different.
(*Jeez, is all this hassle worth it? I don't want to always spend 2 or 3 hours preparing, to fumble around in the dark to listen to 30 minutes of music at an unsociable hour. Better spend more money to fix that )
Could I improve the system and what do I think I would "need" to spend on it? Yes I could and right now, today, I would need to spend about £2k. Tomorrow I WILL think different. Its easier to buy better pressings of records....
"Tweaks", i.e stuff other than the components themselves, have made a huge and transformative difference, so I believe they are always worth exploring. Some have been and are free some are more spendy. Having just spent too much money on a new music room I am still experimenting with system set up and speaker placement. There are free improvements to be had there.
What have I spent on it? Lets leave that at too much...
Where does this leave me? Forget all the above over analysis crap. Philosophically, my system and my music makes me happy. It transports me somewhere else and means I can forget the variable cares of the world at any time of day. As such its priceless and worth every penny of the too much I have spent on it.