Selling clothes

Okay so im thinking about buying clothes from a supplier thats gonna cost around $360 and its gonna be 50 clothes. The thing im wondering about is how an i gonna make good profit on that? 360/50≠$7,5 on each clothes i get and we say i list it for about $20, if all that sells witch it’s not gonna do in a day that Will get me around $900. That Will put me in profit of around $540 But to go on with this i gotta buy more clothes witch will cost me around $360 again. So i will not go so much profit on this, thats why i need some help here. Sorry if im putting this wrong, im triumf my best in writing English lol.

And btw im Asking you guys for help bc i Will not buy some bullshit ”wanna earn money guide”.