Is it okay to feed my cat canned sardines in tomato sauce everyday?

Aren't sardines more expensive than 40-cents a can cat food? If he likes it, sure, go for it, but can't you supplement with a small bit of crunchy kibble like Purina or Friskies? The sardines are good for his skin and coat, as well as the calcium for his teeth and bones, but I would offer him a bit of dry food every day, as this helps keep his fiber intake good and his teeth clean.