How to escape the substitution/replacement part in .NET Regex Replace

Question

I want to escape the substitution part in a regex replace command in .NET:

public static string GetPriceMessage(string data, string price)
{
    var repl = "This is a $1 priced at " + price + " suitable for $2.";
    return Regex.Replace(data, "item_name: ([^;]+); suitable: ([^;]+)", repl);
}

var price = "$15/item";
var data = "item_name: Puzzle; suitable: all ages";

GetPriceMessage(data, price)

I want to make sure price is substituted verbatim. Regex.Escape doesn't work.

Answer 1

You only need to escape $ in substitutions, since all substitutions start with $ . Ie just use:

price.Replace("$", "$$");

See the following question for details: Handling regex escape replacement text that contains the dollar character

Substitutions are the only regular expression language elements that are recognized in a replacement pattern. All other regular expression language elements, including character escapes, are allowed in regular expression patterns only and are not recognized in replacement patterns.

[...]

In a replacement pattern, $ indicates the beginning of a substitution.