Generally, the price of 201SS is lower than 304SS.
By the situation of the continuously rising prices of nickel, stainless steel products which contained low nickel content, low prices is really attractive. And the 201 stainless steel is a suitable choice. Grade of 201 stainless steel is gaining large of market, where 304 stainless steel is  the main choice. 201 stainless steel has a low and stable prices because it uses Magan alternative to Nickel. So, it makes 201 stainless steel has many similar properties and characteristic as 304 stainless steel and has an appearance as same as 304 stainless steel appearance.
The stainless steel is a type of steel that contains more than 11% chrome, so stainless steel has a film self-protect against corrosion. Nickel also known as the main factor to bring stability to the Austenitic phase and capable of easy processing to stainless steel.
304 stainless steel has a minimum content of Nickel of 8%. In elements which formed to Austenitc, there are many elements can substitute for Nickel to create resistance to corrosion. For example: Chrome (Chrome is the main elements that makes corrosion resistance of stainless steel), Manganese (also contributes to stable Austenitic phase), Nitrogen also contribute to hardness, Copper (Cu) also contributed to Austenitic phase stability.
In 201 stainless steel, Manganese was used as the main element to replace Nickel in a 2:1 ratio. We can see by the following chemical composition:
+ Stainless steel 201: 4.5% Niken and 7.1% Mangan
+ Stainless steel 304: 8.1% Niken and 1% Mangan
With this composition as above have reduce the raw cost material to produce a 201 stainless steel. This is a first advantage of 201 stainless steel.