You are correct in the type of cable, but not in price. Monster, for example, is the biggest rip-off there is in regards to touting that you should buy their overpriced cables because somehow they are better. It’s not the brand, but the type of cable used.
In a nut-shell, any brand of the following will produce the same result; find the cheapest of these for the desired result:
HDMI - Offers both 5.1 sound and HD digital picture. Recommended for all HD applications such as HD DVD, HD Cable/Satellite.
Composite cables - Offers lower grade HD picture, but needs a separate cable for sound (usually audio cables that only offer stereo sound).
RCA cables - NOT HD, no matter what anybody says. These are always yellow for video, and read and white for sound (stereo sound only).
Coax (your normal cable TV wire) - Not HD with mono sound.
Coax, my normal cable TV wire, delivers a full spectrum of digital cable channels with stereo, plus numerous HDTV channels with 5.1 surround.
Would tend to agree on cable pricing rip-offs. One general tip is to never buy cables where the TV sets are sold ... whatever the retailer gives up on pricing the set, they'll make back, in spades, on the cables.