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Beyond the rack doesn’t hand-select their merchandise, so it can be a bit of a Crapshoot, but it’s free to sign-up and the deals are incredible!
I realize this reply is coming very late. And sorry.
To be honest, I think a bow-tie is a great idea—especially something that pops with a little bit of yellow to it. Your best bet in my books would be to check out the vintage stores around your area. Bow-ties are big right now in the vintage circuit, and you can general swing a nice one for under $40. Then learn to tie it—youtube has about a million instructional videos.
Have fun at prom (if I haven’t missed it)!