[kelnos]

Depending on the circumstances, that's a big "if". If your not-so-cheap ingredients are one of your restaurant's selling points (even if not explicitly), using cheaper ingredients could reduce your sales such that the savings turns out to be a wash, or a waste.

I think this happens all the time: it's not uncommon to see a restaurant review that goes something like, "I'd been coming here for years, but the quality of food has gone down recently". Granted, you don't know why: maybe they switched to cheaper ingredients, or maybe they got some new cooks that prepare things poorly (or even just differently), etc. But some type of cost-cutting measure could be to blame. And if that person -- and others (and perhaps potential new customers who see the recent bad reviews) -- stops visiting or visits less frequently, those cost-cutting measures may turn out to not have been worth it.