Реализовал сэмпл как вставлять знак рубля в программу

Rouble/IOs/MainController.cs

@@ -1,18 +1,24 @@
 using System;
+using System.Drawing;
 
 using MonoTouch.UIKit;
-using System.Drawing;
+using MonoTouch.Foundation;
+
 
 namespace Rouble
 {
 	public class MainController : UIViewController
 	{
-		private const string Text = "Цена: 100 {0}";
+		private const string Text = "Цена: 100 ";
 
 		private UILabel _label1;
 		private UILabel _label2;
 		private UILabel _label3;
 
+		private UIFont _font1;
+		private UIFont _font2;
+		private UIFont _font3;
+		private UIFont _roubleFont;
 
 		public MainController ()
 		{
@@ -23,37 +29,57 @@ namespace Rouble
 		{
 			base.ViewDidLoad ();
 
+			InitFonts ();
 			View.BackgroundColor = UIColor.White;
 
 			_label1 = new UILabel ();
-			_label1.Text = Text;
+			SetText (_label1, _font1, RoubleType.Regular);
 			View.AddSubview (_label1);
 
 			_label2 = new UILabel ();
-			_label2.Text = Text;
+			SetText (_label2, _font2, RoubleType.Medium);
 			View.AddSubview (_label2);
 
 			_label3 = new UILabel ();
-			_label3.Text = Text;
+			SetText (_label3, _font3, RoubleType.Bold);
 			View.AddSubview (_label3);
 		}
 
+		private void InitFonts()
+		{
+			_font1 = UIFont.FromName ("HelveticaNeue", 18f);
+			_font2 = UIFont.FromName ("HelveticaNeue-Medium", 18f);
+			_font3 = UIFont.FromName ("HelveticaNeue-Bold", 18f);
+			_roubleFont = UIFont.FromName("Ruble", 18f);
+		}
+
 		public override void ViewDidLayoutSubviews()
 		{
 			base.ViewWillLayoutSubviews ();
 
 			_label1.SizeToFit ();
 			_label1.Center = View.Center;
+			MoveY (_label1, -50f);
 
 			_label2.SizeToFit ();
 			_label2.Center = View.Center;
-			MoveY (_label2, -50f);
 
 			_label3.SizeToFit ();
 			_label3.Center = View.Center;
 			MoveY (_label3, 50f);
 		}
 
+		private void SetText(UILabel label, UIFont font, RoubleType type)
+		{
+			char roubleSym = Roubles.GetRoubleSymbFor (type);
+
+			NSMutableAttributedString attrString = new NSMutableAttributedString();
+			attrString.Append(new NSAttributedString(Text, font: font, foregroundColor: UIColor.Black));
+			attrString.Append(new NSAttributedString(roubleSym.ToString(), font: _roubleFont, foregroundColor: UIColor.Black));
+
+			label.AttributedText = attrString;
+		}
+
 		private void MoveY(UIView view, float dy)
 		{
 			RectangleF frame = view.Frame;

Rouble/IOs/Rouble.csproj

@@ -98,6 +98,12 @@
     <Compile Include="Main.cs" />
     <Compile Include="AppDelegate.cs" />
     <Compile Include="MainController.cs" />
+    <Compile Include="..\Shared\Rouble.cs">
+      <Link>Rouble.cs</Link>
+    </Compile>
+    <Compile Include="..\Shared\RoubleType.cs">
+      <Link>RoubleType.cs</Link>
+    </Compile>
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>

Rouble/Shared/Rouble.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+
+namespace Rouble
+{
+	public static class Roubles
+	{
+		private static readonly Dictionary<RoubleType, char> _roubleSymbols;
+
+		public static char RegularSymbol
+		{
+			get { return GetRoubleSymbFor(RoubleType.Regular); }
+		}
+
+		public static char MediumSymbol
+		{
+			get { return GetRoubleSymbFor(RoubleType.Medium); }
+		}
+
+		public static char BoldSympbol
+		{
+			get { return GetRoubleSymbFor(RoubleType.Bold); }
+		}
+
+		static Roubles()
+		{
+			_roubleSymbols = new Dictionary<RoubleType, char>(3)
+			{
+				{ RoubleType.Regular, 'r' },
+				{ RoubleType.Medium, 'm' },
+				{ RoubleType.Bold, 'b' },
+			};
+		}
+
+		public static char GetRoubleSymbFor(RoubleType type)
+		{
+			return _roubleSymbols[type];
+		}
+	}
+}

Rouble/Shared/RoubleType.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace Rouble
+{
+	public enum RoubleType
+	{
+		Regular,
+		Medium,
+		Bold
+	}
+}