It really makes no difference if you buy a cheap HDMI cable or an expensive HDMI cable when it comes to short runs. HDMI is digital, so it will either work or won't. The only thing with a cheap cable is it might fall apart, but I highly doubt it.
VGA is analog, so you could have interference or degradation of the signal. I sorta doubt this is happening, but you never know.
For $5 I'd take the chance and see if it improves your picture quality.