I always edged with my weedeater. Simply turn it 90 degrees and walk it backwards along the driveway. Took practice to not get a crooked edge but not much practice.
I dont remember exactly but once you dial in your oil change interval based on their findings, no reason to use them again unless your driving habits change or oil brand changes.
I wanna say it was less than $25 for the test plus a few bucks shipping to send the sample. I dont think I paid $35...
I have used Blackstone Labs for oil analysis, and they will help you maximize your oil life.
The life of your oil has many variables so request free test kits and they send you small plastic bottles to collect a sample and send it to them for a full report on metals found and other important...