Dual Screening and Video Quality

Black friday is around the corner and I've got plans on buying several things. I currently use an older CRT monitor and would love to get new, widescreen LCD. I was thinking of getting around a 23" LCD, however a friend recommended getting two 19" LCDs and doing a dual screen setup.
He chose 19" because of the sale ($99 for each one). I use a MacMini and the video card of course has space for one VGA (and that adapter to convert so it can work with a Mac computer). So the obvious solution is a splitter of some sort. I did some research on Google. Some guy had a MacMini, had two LCDs he wanted to dual screen with the Mini, and bought some $170 splitter from Maxtor. The guy's site didn't give enough information and I didn't understand all the details from Maxtor's site. Why was this splitter $170? I went ahead and bought a splitter off eBay and paid $4.01 after shipping. I'm going to try this with two CRTs and see the results. Will this $4 splitter produce much less quality than the $170 spitter from Maxtor?

Update: I learned that some splitters will just create a duplicate image of one screen to the other. So both screens would have the same image. Some splitters create an extended image. Also, it was Matrox not Maxtor, my mistake. I'm also assuming what I bought off eBay just creates a duplicate imagine and the device by Matrox creates an extended image.

i would believe that the $4 splitter would just duplicate the image. the way the Matrox splitter works is by installing a video driver that doubles the horizontal resolution of the single vga out and sending half of the image to etch monitor via a splitter.