How often do you upgrade turntable ?

There’s no point if you’re already happy with the performance , and what’s best is subjective and may not be achieved by equipment upgrade. If you live in a city apartment, you’re not going to be able to suppress ambient noise below 40 db, so I always laugh when people start talking about pitch black background. You’d be better off constructing a listening room with noise suppression than upgrading a turntable.

Do most people even level turntables properly and ensure they are located properly in the room?

other priorities, enjoying time with family and friends, paying bills and not sitting there analyzing a Diana Krall album while switching cables.

I’ll give another tangible priority: I have spent money on collecting vg+,NM copies of Blue Note 1st and 2nd pressings- I’d estimate the value to be about $35000. 80 albums. And I play them on an 5K - 6K analog front end.

i think i prioritized the money in the right place. How about you?

Well, I also have $4k-$5k front end but I don't pay for records that much. I don't go over $100 or so per record, though did pay $150 once. That was a promo copy of the first Japanese edition of Bitches Brew by Miles Davis. It sounds best, and I have them all except test pressings.

Maybe not an upgrade but someday I might try idler musical magic and get a Garrard 301/401, but it’ll likely cost >10k to get it sorted out to a high sonic level.