That's about right, though food costs have gone up. As you are a bit of a Known Authority on web forums (hee hee... this time I tease in a non-pointed way), I'm a bit of a pizza guy since I, uh, worked at a Pizza Hut for... uh... well, too many years, and those cost estimates sound correct. When I worked there, the meats were more expensive than the cheeses, as a rule, but the dough and the sauce and the veggies were merest pennies. Our food cost for a 12" veggie pizza back in 1990 was around a quarter, and we sold them for around $9 or so.
Domino's had shitty pizza for a long time simply because they were they only delivery game in town for so long. Once Pizza Hut started delivery in the mid-80s, their slightly-superior quality forced Domino's to up their game or risk losing too much market share. And Little Caesar's has always been apparently happy to hold the cheap-ass pizza niche. In my opinion, the quality of the dough is more important than the quality of the cheese, but since even the expensive dough is dirt-cheap, it's tough to find genuinely piss-poor dough at most pizza joints. One can, however, find superior toppings (especially meats and cheeses), so I think that's where the quality-vs-low-price game plays out.