My circa $1,300 iPhone is made in China, by mostly young women who work 6 days a week, 10 hours a day for peanuts, having only a few bathroom breaks in between. If these very phones would be built in Switzerland, by trained watchmakers making 20 times the Chinese labor rates, paying income taxes and so on, it would cost multiple times that.
A genuine SS Rolex Datejust costs now at least $7,300. Built in Switzerland, it probably costs only $1K to manufacture, the rest is all the marketing, the middle men, and gravy. If Rolex were to build this watch in China, they would save probably over 50% of that. I don't know what it costs to manufacture a replica, but my guess is that your $500 Clean DJ sells for $300 to the AD, and the manufacturers need to make a profit as well after paying for the replication process, location, and their workers.