I agree with the suggestion to check out the Sears outlet on Sherman St, which sells lots of different brands, but of course you have to stop in frequently because it’s hit or miss. Also, don’t forget to check Costco.com for Whirlpool.
Pacific Sales has always offered us the best appliance prices for higher end appliances, especially since they were bought by Best Buy. If you go there, make sure to tell them that you’re re-doing a whole kitchen and are in the market for several appliances (even if you don’t end up buying them all there) and you want the same discount they offer contractors. They’ve always done that for me, but only after some back and forth.