Its the age old question of repair vs purchase dollars. If you were considering keeping the current X to around 150K - 175K, which is not unheard of, then there is a greater than 50% probability of repairs in the following areas:

front suspension - bushings, struts, control arms, CV boots (you know)
cooling system - water pump, thermostat, expansion tank, idler & tensioner pulleys, drive belt, maybe radiator if it leaks - these components should be done as preventative maintenance before 100K
transmission - lucky you with a manual! change fluid every 30 - 60K
drivetrain - change diffs & transfer case fluids every 60K

Talk with your mechanic and get a rough estimate for above repairs and compare that outlay with the additional cash you'll have to spend to get into a newer ride after selling of X.

Me? I like my '04 a lot - just like you said - roomy & comfortable. Just clocked 3K miles on it over the course of the last three weeks all over the Northeast - what a great long distance car. Hauls dogs, garden stuff, Sam's toilet paper, you name it. At 90K I've decided to keep it to 200K (hopefully). I plan to invest in the above repairs, and also expect to replace the auto tranny as well. Maybe I'll get lucky like the guy who ran his X over 300K with very little expense?

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2021 X3 M40i Glacier Silver
2016 X5 xDrive 35i Mineral Silver

Gone but not forgotten
2017 X4 M40i Black Metallic
1985 325e Cosmos Blue
2006 330i Monaco Blue
2006 X5 Ti Ag
2000 528i Ti Ag
1986 535is Black (great ride)
1985 528e Polaris Silver (GTA in NYC)