Buying 'okay' snacks that aren't quite satisfying produces a pattern: eat one, still want something, eat another, repeat. Buying snacks you genuinely enjoy means smaller amounts produce satisfaction. Counter-intuitive but evidence-supported.
What this looks like
If you love chocolate, buy good chocolate and have a few squares. Skip the diet versions that don't satisfy. If crisps are your thing, buy the brand you actually love, eat one portion. Don't buy cheap alternatives that drive overeating.
Most people overeat 'okay' alternatives more than they would eat 'preferred' snacks. The preferred version is often cheaper per actual satisfaction.