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One two or more of the same items are different prices, then look for the reason. If it is just because it is from a high end store then it may be over priced. If it is at the same store with different prices, it is probably due to quality. Buy the quality and save money.
OK, I hope that a Brother walking foot isn't as costly as the Bernina. I almost dropped dead when I replaced my Bernina walking foot and it cost $180. Good luck