Format string by CultureInfo

Use the Currency standard format string along with the string.Format method that takes a format provider:

string.Format(new System.Globalization.CultureInfo("en-GB"), "{0:C}", amount)

The CultureInfo can act as a format provider and will also get you the correct currency symbol for the culture.

Your example would then read (spaced for readability):

<td style="text-align:center">
    <%# string.Format(new System.Globalization.CultureInfo("en-GB"), 
                      "{0:C}", 
                      Convert.ToSingle(Eval("tourOurPrice")) 
                             / Convert.ToInt32(Eval("noOfTickets")))
    %>
</td>