Bri,
Try make a mock-up out of sheet metal and nippers (if possible) and take that to a tooling company. If it's just one tool needed to make the part, then it might not cost as much as you think, and once you have the one tool made, it'll fit various machines so you sometimes have a little bargaining power there as you can take YOUR tool elsewhere.
Chinese firms will be able to make it you the cheapest but you'll normally have to buy a half container or so.
I wouldn't go down the patent route unless it's really something other companies have the time to mess around with. If you say only 5k would want it, max 9k, then they might not be interested at 50p profit an item. Worth considering global sales though as your 5k figure sounds a bit glass half empty to me. 🙂 Believe in your idea matey and give it a bash because you'll regret it if you don't.
Even deano seems to have tried and at least he can say he did now, even though still on tools.