Less work means less cost, more work, more cost.
The cost of a basic Shopify website can be as low as $700 without customizations and integrations. However, that does not include the cost of your domain and the cost of Shopify theme development if you need a custom theme development.
The more customizations and integrations you need and the more complicated your requirements are, your cost will increase. Also, Shopify developer cost is another factor affecting your expense since each developer has a different level of expertise.
A freelance developer may charge less, but a Shopify website development company charges more for their expertise, reliability, and security.