I test my oil, I have a gulf coast by pass filter, and I send the samples to titan labs, and they send the results to gulf coast, who forwards them to me along with any comments. they knew I had the head off without being told because of the oil sample.
I also use the AMESOIL sampling amesoil kits give you a very detailed breakdown.
But I prefer the gulf coast setup, they seem very knowledgeable, and are willing to answer questions and give good pointers.
The only drawback with the gulf coast system is they always try and sell the big four element filter system, which in my common sensical opinion is over kill, I bought the single element filter, and it works fine. I guess if I did heavy haul or something the big four element filter would make sense, but in most truck applications the four element system is severe OVERKILL.
By the way testing on the first oil change is not a waste, as you could find coolant or fuel in the oil, which if your thing of buying a truck the 19 dollar test may have just saved you thousands down the road. True you won't a a basis to compare wear metals, but you won't need it if a cylinder wall is cracked and coolant has seeped into the oil.
So yes pull a sample if your considering buying a truck (Used truck anyway)