Using String Format to show decimal up to 2 places or simple integer

I have got a price field to display which sometimes can be either 100 or 100.99 or 100.9, What I want is to display the price in 2 decimal places only if the decimals are entered for that price , for instance if its 100 so it should only show 100 not 100.00 and if the price is 100.2 it should display 100.20 similarly for 100.22 should be same .
I googled and came across some examples but they didn’t match exactly what i wanted :

// just two decimal places
String.Format("{0:0.00}", 123.4567);      // "123.46"
String.Format("{0:0.00}", 123.4);         // "123.40"
String.Format("{0:0.00}", 123.0);         // "123.00"