Suspicious DVI cables?

Hey everyone,
I am wanting to connect my vaio desktop to my tv via dvi. My manual says I need a dvi cable and a 3.5mm L/R audio cable. I looked for the audio cables and they are like $25 at best buy, which seems reasonable. However, the dvi400 cable by monster is 79.99 which is in my opinion a bit high. I did some searching on ebay and found what i think is the same cable for $9.99! My question is are the cables on ebay the same ones as in stores? Or are they an inferior product? I can understand them being a little cheaper on ebay, but not like 70 dollars cheaper, especially on an 80 dollar product, it just seems a bit too good to be true. Any experience or advise on this is greatly appreciated
Thanks in advance,
burner413

EDIT: What DVI cable would you suggest? My tv has both hdmi and dvi ports. I would just like to know if dvi to hdmi offers better quality that dvi to dvi, and what model is the best. On ebay the dvi to dvi 400 is 9.99, the m500 is 59.99 and the dvi to hdmi 800 is 29.99. I thought the higher the x00 number was the better the cable, but from the prices i guess not. Arghhhh im soooo confused...