The phrases "How much is this toy?" and "How much does this toy cost?" are essentially asking the same question and can be used interchangeably in most situations. Both are commonly used when someone wants to inquire about the price of a toy or any other item. There is no significant difference in meaning between the two; they are just different ways of phrasing the same question. You can use either one depending on your preference or the context of the conversation.

They mean the same thing. The more formal way to say it is ‘How much is this you’ but it can be shortened and people will understand exactly what you are saying.