Best solution: simply buy snap caps for Both this used PO1 and the used Sig P229 in .40. Roger that?
That is the approach many take to address wear when dry-firing.
However, it might be wise to have spares of these parts on hand anyway
if this is a gun you intend to shoot a lot. It really depends on a couple of factors: 1) are you keeping the gun stock, and 2) how tolerant of "down time" are you if you have a part fail?
If you keep the gun stock and have a failure, you could possibly get replacements under warranty but that would take time to work out. I keep spares on hand because I use CGW upgrade parts to begin with and - even though I have a spare P-07 - I don't want to be waiting a week to get a replacement part sent.
All of this hinges on how much and how often you shoot the gun, though. Think of it like you would if you knew you were going to put a lot of miles on your car - you'd plan in advance for the parts and maintenance it would require to keep the car on the road. Same concept, really.