Ya, I almost went the Aquatraders direction as well recently to start my second tank (you know, being a poor PhD student and all...). I was looking at the MH mostly and those seem to be not of the best quality. The t5's on the other hand I have heard some decent things about and, like they said above, switch to better bulbs. The one thing about the t5 units, and someone please correct me if I am wrong, is that they don't have reflectors, thus your output is not as stellar as it could be.
For the same price point but maybe a little better try the Fishneedit units (
http://www.fishneedit.com/t5ho-ligh.html). I've heard good things about them. They've got reflectors and everything.
If you have a friend in the states or access to a PO box, try Amazon of all places. They have retardly cheap deals on good lights from time to time... they don't ship to Canada though.
Finally, ask around this site. I got a wicked MH system from someone here for a good price and I could not be happier (It's a little overkill... but hey, go big or go home, right?). I'm sure there is someone with some lights for sale... right guys and gals?