A line of argument, is the same as a line of discussion, as a point of interest, as a perspective being established.
There is no confrontation in it Gomez, and unless you can coalesce a line of argument, or if you like, reasoning, then you cannot effect an informed debate.
This is where you are, shelf unit put forward a line of argument about pricing, you 'chose' to sidestep it, or avoid it because you coudn't argue with his 'reasoning', because he was right.
Call it by whatever name you want the fact is you have not answered his statements refuting your line of reasoning because he is right.
So seeing as you clearly have the time to answer, why not make the small amount of effort and address his salient points?
Oh thats right you couldn't so you covered it up in a smokescreen like a kid who can't do his homework because it's too tough...
An entirely false statement and the proof is just a bit further up the page. ;-)
Shelfunit sent me a PM because he thinks you have him on your ignore list but I told him it's just that you don't have an answer for his logical reasoning.
So you elect ignore his 'discussion points'.
A discussion or argument of a friendly and constructive nature needs both parties to acknowledge the points of the other but you, and I quote you here, "Can't be bothered." to answer any lines of discussion that you find to difficult to deal with because they are contrary to your own ideas and you can't argue with their veracity.
Of course you don't have to answer shelfunits post, but by ignoring posts you can't answer with logic or deal with by way of logical discussion and then making vacuous excuses for doing so means you have nothing left to offer the 'discussion'.
Surely it's better to be honest and keep your credibilty and respect?