Hi, it is better to create your own application, and on the operating system iOS, since most of the planet, covered by this operating system. The content of the app, it’s not expensive, it’s expensive to create, but it’s very cost-effective. Hire people who can make you a good advertisement and it’s done!
Quick question, do you really need to build an app to sell your clothes online? If you’re just starting I wouldn’t recommend starting like that. I don’t know if that’s your situation or not but something to consider. You can test your market online for free before spending time or money on building an app. There are plenty of options that are already built to start.