It is a little unfair since I am a Porsche tech, but I rebuilt my 2000 S. I bought it with 2nd gear grinding from PO's attempt to be a race driver. The locker/dog teeth are VERY small, and get rounded off quite easily. The GBOX detent is a great upgrade. If can compensate for light wear on the dog teeth, but if they have started to chip then it will only be a band aid.
If no bearings are needed, and you can replace the 1st/2nd locker assy, get Bbox detent, and replace 2nd gear. Labor will only be a few hours more than used transaxle to repair, so if would come down to price of used unit vs. gear and locker.
If there is ANY suspect of bearing contamination, then labor to do pinion bearing will shoot up. Also the bearings are all quite expensive.