Nick here from Shopify.
Great question! I completely understand where you are coming from as this is one of the most requested features from Shopify store owners to our team. In terms of having multiple currencies at the checkout, it is still only possible for Shopify Plus store owners. I looked into some apps for you about this and while there are many currency switcher apps a store would still need to be on Shopify Plus to enable it to display the customer's local currency at the checkout portion of a sale. For example, the Auto Currency Switcher app displays the following in the app description on the app store:
The more requests which come in for specific product upgrades the better our team knows and is aware of what store owners such as yourself need and want, so feedback like this is invaluable. What I will do is add another feature request to the development team on your behalf, but for now, to avail of this, you must be on the Plus plan.
Hopefully, this helps and answers your question.
All the best, Nick