Totino's is probably the closest comparison I could think of. For those who don't know Totino's is an extremely cheap and pretty awful tasting frozen pizza brand. But at least they know they're cheap and price accordingly. Happy Joe's is way more expensive than places like Pizza Hut and Dominos and can't match their quality. Just look at the photos on here, not appetizing.
Side note: I've noticed that the majority of the people who like this place have mentioned that they grew up on this food in the Midwest. As someone who was born and raised in the Midwest this embarrassed me. Let's have higher standards please.