Cheaper lures will catch fish, but you'll see far more issues with cheap lures not running straight or breaking. Suspending jerkbaits especially - cheaper ones will not always suspend the same. No lure really suspends perfectly, but the high-dollar ones will be much more consistent. Of the two "Springer 100" knockoffs of the LC Pointer I've got, one is a slow sinker and the other suspends or floats extremely slowly. I saw a pic once (on this forum, but that was years ago) where a guy took a bunch of the Springer 100 lures and put them in an aquarium together. Most ended up on the bottom, a few suspended, and the rest floated. That's par for the course with knockoffs.
If you buy, say, ten Lucky Craft square-bill cranks and ten Strike King KVD cranks and compare them, the LC baits will all look nearly identical. The paint on the Strike King lures will have noticeable inconsistencies, and the lure bodies themselves will not all be put together with the two halves lined up. Take them out on the water and odds are you'll have to tune more of the SK lures than the LC's.
As far as fish-catching, fish are far too finicky from one day to the next. Some days they'll hit one lure and others they want something completely different. It comes down to what each angler believes he/she is getting the most bang for their buck out of. The Megabass Vision 110 is extremely popular, but I couldn't say whether it will catch more or bigger fish than a $3 knockoff.
I've heard far more complaints about Strike King® lures than lures from any other big-name company. I caught a lot of fish on the Red Eye Shad this year, but I know a lot of guys have had problems with them swelling up if left out in the sun. Broken lips, water entrance, untunable lures, those are all things that occur with a much higher frequency in cheaper lures.
Plus, the high-end lures usually look better than cheap ones. I'm very susceptible to being "caught" by a lure with a well-executed build and finish. Take a gander at this one:
[i was trying to post an image here, but this forum won't let me. Try this link instead.]
No, I don't have one. Yes, I want one.
Oh yeah, once you catch a fish on a lure you built/painted, you're a hopeless addict. You've been warned.
Tight lines!
Ben