Expensive? Fuel in general is expensive. 2 cycle oil at Walmart is $13.00 a gallon. So not a real big expense. If the truck holds 24 gallons I just added 24 ounces of 2 cycle oil. Those diesel additives are quite expensive as well and you have to be careful of what you run as some have a lot of alcohol in them. Those are supposed to not be good in the high pressure systems like the dura max engines and so on.
I am no expert just my personal experience of what I did. To each his own I guess.
Matt