Breezify's plans are priced around credits, and it helps to know exactly what spends one before you pick a plan or a model. A credit is consumed by a generation, building a new app from a prompt, or refining an existing one with a follow-up message, and the cost of that generation scales with the model you choose for it, not with the plan you are on.
This is why model choice and credit usage are really the same decision. Haiku generations cost the least, which makes it the right default for small apps and for early iterations where you are still exploring what you want. Sonnet and Opus cost more per generation but handle more complex requests in fewer tries, so a single Opus generation that gets a hard feature right the first time can end up cheaper in credits than three Haiku attempts that each need correcting.
Viewing a live preview, deploying an app, attaching a custom domain, and reading analytics or revenue for an app you already built do not consume credits. Only the act of generating or refining code does. That means once an app is built the way you want, running it and sharing it costs nothing further against your plan.
If a plan's monthly credits are running out faster than expected, the fix is rarely to upgrade first. It is usually to switch the default model for straightforward refines down to Haiku, and reserve Sonnet or Opus for the specific changes that actually need the extra reasoning, the same one-tier-up-only-when-needed approach worth using when building the app in the first place.