It may not be as cheap, but I use BBQ sauce instead of ketchup.
I don’t think I’d like that personally. Too sweet for pizza IMHO, but I imagine it would work in a pinch.
Last time I bought barbecue sauce, it was to try to duplicate the old Arby’s Beef and Cheddar recipe (that is another one that has gotten barely edible, but I used to love them.) (I have very plebeian tastes.) Anyway my attempts to duplicate that tasted pretty good, but man, they were messy; I had melted cheeze whiz and BBQ sauce squirting everywhere, with every bite.