Normally if a bike shop/car mechanic/joiner/decorator/plasterer's job is spiraling overtime or over spend, they come to the client and consult. They don't just spend like crazy to the tune of 3x the budget on a whim that the client will almost certainly have pockets that deep.
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Your spokes should hacve cost between 70p and £1 each. Add that to the quoted price, tell them that's what you owe them, thankyouverymuch.
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