Try http://www.TheZeb.com under Q-Logic in the manufacturer's list. They sell them for 150 a pair which is the absolute cheapest I think you can find them for, other than making them yourself.
You may need to cut the Universal's to make them fit your car.
The cheapest kick panels would be the ones you build yourself Totally custom, unique, good project to work on...learn to perfect your fiberglass skills.