Lots of good info above.
In Summary:
1. Parts Availability is an issue for the unique safety system. Mags, barrels, other parts mostly interchange to 59xx pistols. 5926 are stainless frame - pretty robust unless abused - so if its had the recall and doesnt have any issues, parts availability may not be an issue.
2. Avoid disassembly of safety system - field strip ok but dont dive deep unless you are looking for a real challenge.
3. Grips impossible to find - there are some aftermarket copies but based on another thread here they appear to be problematic. No real option to replace grips.
4. Majority of those for sale seem to be Import Marked (less desirable in my mind).
Original 5926 (TFA-TFC prefixes mostly early 1990) had early D shaped trigger guard. Late = late 1990-93 (TFE, THB, TVB, TZK) had rounded trigger guard. Early slides generally had 5926 marking on left side of slide and "...Parts Must Agree..." on right of slide. It appears all had Novak sights (no adjustable or night sights unless 1 off Special Order).
If I could find a nice late one (good condition, no safety issues, good grips, no import marks) under $500 I would grab it. If buying online dont forget shipping, fees, taxes would probably bring that up to $600. Mags are not an issue - (still available used and often new SW original). Matching box and extra mags would be a plus - person to person avoiding shipping, fees, taxes would be a plus.