They never have in the past, for pilots. There will be a uniform salesman there to tell you what to get. Most Navy guys can use their black pants, shoes, and double breasted jacket, just have to change out the buttons and put three stripes on the sleeves. Us AF guys had to buy a double breasted jacket, not cheap.

I just priced one in the ATL A concourse pilot store, it was about $225, just for the jacket, a new hat was about $59. I got a new pair of black pants on sale at JC Penny for about $40. Google "Pilot Pete's uniform supplies", it's an online uniform store, run by a Delta Pilot. I got 3 shirts there for about $16 each.

$400 should cover everything, assuming you already have black shoes.