this is a subject dear to my heart and it boils down to how much is your time worth.
Was getting a stumble from a bad coil pack in my 328. Found 3 makes when I pulled them out. Easy job to replace them all and at $40 and 30 minutes each vs. $175 for all 6 and 45 minutes total, seemed a better way to go replacing all 6. 5 old against 1 new in the pic. Preventive replacement saves a ton of time and hassle because the next time one goes, you know it will be at an inconvenient time.
Just a no brainer to do all of them at one. One more goes bad and I'm negative. Another, very negative.
