See this is very interesting issue.
User on my website uploads a design for 3D printing and then we offer him different prizes for different materials. For an example, if you upload a model and want us to print in a specific material, we will give him a quote in American Dollars. ( User gets to choose his own currency in account settings ).
But now if he opens the same website in another tab and then changes his currency settings from USD to Japanese YEN, what should be the behavior or message in first tab where he has all the rates in American Dollars.
- Currency automatically gets converted from USD to YEN.
- We notify user on the first tab that currency has been changed and he needs to refresh the page.
- Nothing happens on the first tab but when he clicks the link for prices in his email again ( we send user a link where he can check the rates for that specific model ), he sees converted rates.