To convert prices in euros in dollars it means you should make Currency Conversion. In order to do the currency conversion you should take several steps in Excel:
1. Select a blank cell next to the price in Euros and enter the formula =NUMBERVALUE(A2,",",".").
Now you will have the amount. If you also want to have the symbol for dollars you should:
2. Format the cell: Right click-> Format->Currency and select the currency.