Many folks cannot tell the difference in HDMI and component as far as picture goes. It's also depends greatly on your TV set and the cable box, either of which could reduce the quality of the signal. There's additional gains from HDMI in the audio department, but most people don't have HDMI receivers nowdays. HDMI 1.3 meets specs to carry 7.1 signals uncompressed. Still, 1.3 HDMI receivers are few at the moment and pricey. HDMI is digital, meaning the signal wont be reduced by outside interference like component, composite, s-video do. If you want to compare, simply hook up some component cables. If you don't have any, a couple good pairs of RCA cables should give you the same results.
Paying more than $10 or $20 is way over-paying. If you need another one in the future, check out monoprice.com or other quality shops that the pro home theater enthusiasts love.