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.
How often do you upgrade turntable ?
The table itself, not arm or cartridge.
And when you do, how far do you go ? Big steps, small steps ?
I got my Nottingham Spacedeck more than ten years ago and have no intention to replace it. I would have to jump high for the upgrade to make sense. One day perhaps.