Hi! If you want to offer different price using local currencies among multiple markets, it's better to run multiple shops serving different domains. For example, set up exampleshop.com for US market, exampleshop.com.au for Australia market etc. In this way, it's better to control price, shipping cost, stock availability difference among different markets while allowing local currencies.
You could auto direct your visitors to correct website URL links based on their geolocation. For example, use Geo Redirect tool. You can easily set up visitor redirection rules easily with a few steps. No code is necessary. The service will generate code for you to add to your website. Shopify is perfectly supported.
Hope it helps.