I want your help in determining the estimated website design cost of my imminent business which is primarily an online mobile repairing services website with an e-commerce-based mobile accessories shop.
This is a great question! Many of my clients here at www.Unthink.me typically start off with this question because there are many different price points that simply add to the confusion. The short answer to your question is that most designers will price what they think their time is worth, not what the commodity or service is actually worth whether is priced by the market or others in the industry. That is why a website with no e-commerce could go for either a few hundred dollars to thousands of dollars.
Depending on the designer selling it and the person buying the web design service. As Unthink we do websites of all sorts from a few hundred dollars to hundredths of thousands for our larger clients.
Please keep in mind that your business shouldn't drive the cost of the website. Features and upgrades do, however, but it does not mean they come or should come at a high price. If you want an e-commerce capability, you can try site builder like Shopify or even something like Wordpress with a theme like Avada - these are not super simple to pull off but with some technical capabilities you should be able to get things done. If you hire a designer to help you with these, the cost should also be significantly lower.
Web design has become a commodity, don't get charged for it like its a luxury. Web designers need the income to compete against cheaper alternatives which is why most over price their time.