yep the best cheap mix is Vitalin Pet Food(it's a dog food made from maize meal, meat and bone meal) stinking cheap from farm shops as Dan said mix it with Molasses or treacle but this time of year feed small amounts of food.
I have caught carp on:
meat,( Peperami works well)corn, chickpeas, lupins,dog biscuits, small cooked potatoes,worms, green beans,cheese, slugs, mussels, maggots,casters,worms, plastic corn, dog food cat food good old boilies, thats all i can think of at the mo but give me 10 min and i will come up with some more