Hi Zicklee,

W.r.t your query, I have gone through it and tried to replicate it.Few recommendation as per my understanding are as follows :-

1) Assuming that multi currency option have been assigned to the user with which we would Log In.

2) Now as we have multiple currency feature enabled,first thing which needs to be done to view invoices in different currencies is that we need to configure a price list in which we can assign the currency as required. As by default the currency of the company is in Euros. Even if we change the default currency of the company to any other currency we won't be able to view it in invoices. You can view the default company currency in Setting>Companies>Companies>Configuration.

3) Now by only enabling multi currency we won't be able to view invoice in different currency as expected by us. For this we need to configure a price list.The configuration of price list can be done by following Setting>Configuration>Sales>Quotation& Sales Order>Customer Feature>Use price lists to adapt your price per customers.

4) On doing so we will be able to see the option of Price List under Sales>Configuration>Price List. Here by default there will be a price list in currency “Euros”. Now we need to configure a new price list with currency as “USD”.Now you just need to add an item in the new price list configured if you don't want any specific rule for specific products.

5) After doing so lets get back to creating a Sales Quotation, once we click on Sales Quotation we can see the option of Price List on the form. Here by default we can see that “Euros” is populated, but we can change it to any price list based on our currency and doing so will enable you see different currency symbol on your invoice.

Hope this helps.

 Cheers!!.