<apex:outputText value="{0, number, ###,###,###,##0.00}">
<apex:param value="{!Invoice.Amount__c}" />
</apex:outputText>€
This worked
& + euro; is for €
<apex:outputText value="{0, number, ###,###,###,##0.00}">
<apex:param value="{!Invoice.Amount__c}" />
</apex:outputText>€
This worked
& + euro; is for €