There is no one-size-fits-all answer to this question, as the cost of building a Shopify website will vary depending on a number of factors, including the size and complexity of the site, the cost of any third-party themes or plugins, and the hourly rate of the developer or agency you hire to build the site.
Generally speaking, you can expect to spend anywhere from a few hundred dollars to several thousand dollars to build a Shopify website. If you're on a tight budget, you may want to consider using a Shopify theme, which can cost anywhere from $100 to $200. You can also find a number of free and paid Shopify plugins to add additional functionality to your site.
If you're looking for a more custom solution, you'll need to hire a developer or an agency to build your site. The hourly rate for developers can vary widely, but you can expect to pay around $100 per hour for a good Shopify developer.