Hello, dear friend, I will recommend a powerful tool named ShopMaster which can monitor amazon source product price and update your product price in your store. This feature is also apply for Aliexpress & eBay source products. Hope that helps you. :o)
You can refer to Dropshipmate shopify app which has a feature to set Daily Auto Update/Sync. It can help you sync your shopify prices according to the amazon prices. You can also see 18+ websites listed in this app including Aliexpress, Walmart, Amazon, Ebay, Dhgate etc., This app also helps in importing Product Reviews too.
All the Best...