How much for his suit?

Just wondered.. Since the dresses usually are really important and expensive, how do your FH feel about their suits? Is a wedding suit any different than a normal suit? Do they cost usually more? Compared to your dresses, how much does a suit cost? 1/2, 1/3 or much less? My Fiance really does not care about what he wears, but i fear he will regret it later and that`s why i want to make sure he gets something appropriate. Thanks in advance for any advise.