Agreed
Huge difference between a $40 stick and a $150 stick no doubt. But between a good $150 stick and a $400 stick not near as much, especially if you have one built.
I have a $120-$150 St Croix Avid series I believe that I used to use quite a bit, but handed down to my boy. The difference between that stick and a his old $20 zebco kids compo is almost as much as the difference between that Avid and an NRX as far as the way it feels. Almost being the key word; I think the high end rod is farther ahead of the $150 rod than that rod is ahead of the zebco.
Like said before, it's not saying you'll catch more fish with the upgrade, that ain't the argument. Argument is in the quality/feel of the rod. Lots of good analogies up there having to do with cars, guns and sex positions that I got a kick out of and pretty much sum it up.