Marketing for cheap ---15 YEAR OLD

Hey guys I'm 15 years old and ran a successful landscaping business this summer that was HIGHLY profitable. Very little overhead. I marketed that for free by handing out flyers. I'm starting a "leather goods" business starting by selling handmade wallets. I know the process and they aren't bad quality. My question is I need help marketing them. I'd be directing the marketing campaign towards the product on amazon or my future ecommerce site. Please give me suggestions and how much TOTAL it would cost me. Thanks