According to men.style.com, there is such thing as the ‘Sartorial Equation’.
Shoe x 3 = Suit = Watch/10 = Shirt x 6 = (tie) 10
Assuming a price of a shoe cost a dollar, the price of your suit should cost 3 times more (3 dollars; the price of 3 shoes, 6 shirts), which is one tenth the price of your watch and so on. These are useful guidelines to budget your purchases.
Image by Jak & Jil