Risk/reward on buying equipment to do this now is too high. I would not bother. And I certainly would not mine on a hardware I use for other things - mining is taxing on your hardware - noisy cooling solutions required, big power supplies, and may give other system instability - most miners overclock certain aspects of their hardware (such as memory speeds) - I wouldn't want my trading PC running that sort of thing in the background due to risk of it crashing the system.
The problem for me is that things move so fast. You could buy a rig now for a few $k and it sounds like it could be redundant within a couple of years. My current laptop is 10 years old. It's a bit slow, and sure I could probably benefit from upgrading to a new model, but it is still perfectly usable. I doubt you could count on a rig being any use in 3 years, let alone 5 or 10 years.
Forget years - it'll probably be redundant (unprofitable) in 6 months. Your laptop is certainly has a reasonable chance (5-10%) of failure each year and your storage probably more. I hope you have good backups.
It does play up from time to time (screen/gpu definitely on the blink). I know it's only a matter of time before it dies, which is good because it's a constant reminder to keep it backed up.