How long should I keep this laptop (Dell 7567i7-7700hq, GTX 1050ti, 32GB RAM, 256GB SSD, 1TB)? I use this laptop for programming (+ some deep learning and a bit of 3D modelling). I've had this one for over 3 years and it's running pretty good and meeting my needs. No gaming. It's a dual boot and I use Linux half the time.
The battery still lasts for 3-4 hours of programming and browsing. I don't carry it around with me.
I think the laptop is worth around $400-$500 if sold now. The upgrade will cost more than 25% of it's current value and it's not going to change the value of the laptop in any meaningful way. I would like a bigger SSD for convenience but can live without it.
Edit: Bought the 1TB 970 Evo plus
If everything else is good then a 1TB SSD upgrade sounds worth it imo.
Worse case scenario, the laptop fails or no longer meets needs, you could take the SSD out and use in a new laptop (assuming it has a second SSD slot).