用正则表达式替换C#美元问题

我如何使用Replace-method直接执行此操作？我只是通过添加一些我立即删除的临时垃圾找到了一种解决方法.

请参阅问题的代码：

// We want to add a dollar sign before a number and use named groups for capturing;
      // varying parts of the strings are in brackets []
      // [somebody] has [some-dollar-amount] in his [something]

      string joeHas = "Joe has 500 in his wallet.";
      string jackHas = "Jack has 500 in his pocket.";
      string jimHas = "Jim has 740 in his bag.";
      string jasonHas = "Jason has 900 in his car.";

      Regex dollarInsertion = new Regex(@"(?<start>^.*? has )(?<end>d+ in his .*?$)",RegexOptions.Multiline);

      Console.WriteLine(joeHas);
      Console.WriteLine(jackHas);
      Console.WriteLine(jimHas); 
      Console.WriteLine(jasonHas);
      Console.WriteLine("--------------------------");

      joeHas = dollarInsertion.Replace(joeHas,@"${start}$${end}");
      jackHas = dollarInsertion.Replace(jackHas,@"${start}$-${end}");          
      jimHas = dollarInsertion.Replace(jimHas,@"${start}$${end}");
      jasonHas = dollarInsertion.Replace(jasonHas,@"${start}$kkkkkk----kkkk${end}").Replace("kkkkkk----kkkk","");

      Console.WriteLine(joeHas);
      Console.WriteLine(jackHas);
      Console.WriteLine(jimHas);
      Console.WriteLine(jasonHas);




Output:
Joe has 500 in his wallet.
Jack has 500 in his pocket.
Jim has 740 in his bag.
Jason has 900 in his car.
--------------------------
Joe has ${end}
Jack has $-500 in his pocket.
Jim has ${end}
Jason has $900 in his car.