The cost of developing a basic mobile app and registering it on Apple's App Store can vary widely depending on various factors, including the complexity of the app, the features you want to include, the platform (iOS or Android), the location and expertise of the development team, and other considerations. However, I can provide a rough estimate for a basic mobile app.

1. Development Costs: - A basic mobile app typically costs anywhere from $5,000 to $50,000 or more, depending on the complexity of the app. Simple apps with minimal features tend to be on the lower end of the cost spectrum, while more complex apps with advanced functionality will be on the higher end.

2. App Design: - Design costs can vary, but for a basic app, you might expect to pay around $1,000 to $5,000 for app design and user interface (UI) work.

3. App Registration: - The cost to register as an Apple Developer is an annual fee of $99 (as of my knowledge cutoff date in January 2022).

4. Miscellaneous Costs: - There may be additional costs for app testing, quality assurance, and any third-party services or APIs that your app relies on.

5. Ongoing Costs: - Keep in mind that after your app is registered on the App Store, you'll have ongoing costs for maintenance, updates, and potential server hosting, as well as marketing and promotion.

It's important to note that these are rough estimates, and the actual cost can vary significantly. To get a more accurate estimate, you should consult with app development agencies or freelance developers and provide them with detailed specifications for your app. They can then provide you with a more precise cost estimate based on your specific project requirements.

Also, keep in mind that while you can publish your app on the App Store for an initial fee of $99 per year, there may be additional costs associated with maintaining and marketing your app over time. Additionally, the cost of app development can be influenced by factors such as location, the complexity of the app, the expertise of the development team, and any ongoing support and updates required.