Enter the appliance model number in google (or search engine of choice), with and without "parts" added, and you'll probably bring up a number of suppliers. If you can find from that a common parts model (where three or four different "brands" were actually the same thing with different names & numbers) you may get better parts results from one of the other brands. I think my Kenmore turned out to really be a Whirlpool.
In contrast to @mrtidy I found better deals than that supplier, though if you want to use them I suggest loading up your cart, filling in enough information that they have your email address, then closing the session without placing an order - they'll offer you a discount code in a day or less (and spam you for the rest of your life, but that's what junk mail filters are for.)
Mind you, I got a better and faster to the door price from an alternate supplier than the discount code at that suppler would have gotten me.
On the third hand, I'd be highly dubious of getting into a second-hand dishwasher that was not in perfect operating order. They don't age well, in my experience. But I guess you are already there.