Validate decimal value to 2 decimal places with data annotations?

You could use the RegularExpression attribute, with a regex that matches your criteria. There are a whole bunch of expressions here that involve numbers, I'm sure one will fit the bill. Here is the link.

This will get you started, though it may not be as inclusive as you want (requires at least one digit leading the decimal point):

[RegularExpression(@"\d+(\.\d{1,2})?", ErrorMessage = "Invalid price")]

Note that it is difficult to emit a precise error message because you don't know which part of the regex failed to match (the string "z.22" has the correct number of decimal places, for example, but is not a valid price).

[RegularExpression(@"^\d+.\d{0,2}$",ErrorMessage = "Price can't have more than 2 decimal places")]
public decimal Price { get; set; }

This will cater for 0 to 2 decimal places, or none at all.