I put together a suit for my avatar a while back. Switching in the Bowler Hat I get this:

Total Value: 9,633 Gold
[Item Information]Item List:
White Bowler HatBlack Zoot Suit CarlangoWhite T-ShirtBlack TieDashing Gentleman Onyx VestDashing Gentleman Onyx Tuxedo TrousersI used the Black Dress Boots for shoes since I was broke at that point, but I'm certain there's a better pair of shoes available so I've left that empty.
That said, it'd be good if the outfits were cheaper. A couple of items in that suit are Cash Shop-only, so the price in the MP would increase considerably if they were removed. Prize and Joy items vary a lot in how much they go for since you get them with tickets, and there's also the issue of how much gold the average guild member has and is willing to spend on the outfit. The PAU suits are around 6k, a fairly easy amount to get, but I can say from personal experience that the only time I have 15k on hand is when I'm saving for an expensive item.
That said, use the Bowler Hat in the outift. It's a nice item.