A couple of thoughts on your question. First, the cost difference between “inexpensive” and “good smoking pellets” is pretty insignificant in the overall scheme of things.
Then, there’s the issue of “non-problematic pellets.” “Inexpensive” pellets are “inexpensive” due to the materials used to make them and the quality control during and after manufacturing. For the sake of discussion, lets just call those “inexpensive” pellets “cheap.” They are cheap because they are made from cheap materials like scrap wood from furniture manufacturing, bark, etc. That potentially leads to poor burning characteristics and the imparting of an off flavor.
As for lax quality control, that can show up in a wide variance in the size of the pellets, with excessively long ones potentially jamming up the feed auger. And, cheap pellets may also include significant amounts of sawdust that potentially leads to other burning issues.
My point here is, how much will you save on a given cook by using cheap pellets? A dollar? Maybe two at most. And, what is the potential cost? Ruined meat, jammed augers and random burning problems. Seems to me that is false economy. YMMV
