honestly, one of the oldest proven methods is buying low, and selling high. buy products from china via taobao/aliexpress. and resell locally or online in your country for a reasonable higher price. you can list items through facebook buy and sell groups, or craigslist. or on a personal website etc.
i highly reccommend investing your $200 in product that you can buy in bulk. for example i bought tempered glass screen protectors for phones, for $1 each. paid $200 for 200 pieces, charged customers $20 for each screen protector. plus i personally installed them on their phones.