Products showing as $0 in cart

I have an issue with only some products. They are set up correctly, show correct price on the product page then show as $0 when added to cart. It's not for all products, only some which were added recently (those effected are currently disabled). Any assistance would be great. I'm not a programmer so need "layman's" instructions if I have to modify any code. Please help! Site is http://electricaldistrict.com.au