I don't know what kind of "high-end" systems you've seen, but it must have been an idiot who set it up because you can't really go too wrong with expensive unless it was put together horribly.. That's not to say you can't go right with cheap... but monster still makes fairly good quality cables.
The thing is, you have to have a REALLY good display to see any improvements just by switching to a certain brand or make of cable. Hell, there was minimal difference in quality of picture switching from component to DVI on our 61" DLP. Noticeable, but minimal. Was it worth the extra 75 bucks to go to DVI? Yeah... I think so (if not for the quality, then for the peace of mind, lol). But will it be worth it to you to spend an extra 50-70 to just switch to a "higher-end" version of what you already have? Probably not. Unless, like already said, you're running 20+ ft of cable accross a room that may carry alot of interference straight from one device to the display, I don't see the need to spend more money.