Skype for Linux now offers Webcam support? Nice. And just like Starcraft 2 slogan: "It was about time...".
I think Webcams are well supported in Linux (unless they started to make "paper weight"-like cams like they do with printers and modems). Go for a price that you think is adequate for a webcam. I have myself a cheap canyon and never thought it would work in Linux, but it did out of the box