Short answer
A "replica Patek Philippe 5304" is not a cheaper version of the same watch. It is a counterfeit of a Grand Complications piece, the 5304/301R, whose whole point is a minute repeater and a tourbillon. Those two mechanisms are the hardest things in watchmaking to build, and no factory in China or anywhere else is putting a working minute repeater into a watch that sells for a few hundred dollars. What you get is a case that resembles the shape, a sapphire dial that resembles the look, and a movement with a spinning cage that resembles a tourbillon from across a room. Buying one in the US is also a federal crime, not a gray-market loophole.
What the real 5304 is
Patek Philippe built the 5304 as a self-winding Grand Complications model in rose gold, with a sapphire dial that lets you see the repeater mechanism sitting under the surface. It chimes hours, quarters, and minutes on demand through a slide in the case band, and it carries a tourbillon in the movement. Retail sits in the high six figures in US dollars, and secondary prices on the rare pieces climb from there. That gap between retail and what people pay is the entire reason a counterfeit market exists.
Why the "tourbillon" on a replica is mostly a prop
A real tourbillon puts the escapement and balance wheel inside a rotating cage to average out gravity. Building one that actually keeps time costs more than most people spend on a car. Counterfeit makers solve this with a decorative rotating cage driven off the movement, or a stamped plate shaped like a cage, and the watch underneath is an ordinary automatic. The chime is worse. A minute repeater has racks, snails, hammers, and gongs tuned by hand. A counterfeit 5304 has none of that. Some listings add a speaker or a quartz chime to fake it.
The legal side in the US
Trafficking in counterfeit goods is a criminal offense under 18 U.S.C. § 2320, and that covers the buyer in some fact patterns and the seller in most. Customs and Border Protection seizes counterfeit watches routinely, and a seized package means you lose the money and the watch. Patek Philippe actively pursues counterfeiters. If you sell one on a marketplace, you are the one exposed, not the factory overseas.
Spotting a fake 5304 if you are shopping secondhand
- Ask for the chime on video, with a time check. A real repeater rings the correct time. A prop rings a recording or nothing.
- Weigh it. Solid rose gold is heavy. Plated brass and steel copies feel light in the hand.
- Look at the case back edges and the lug finishing. Counterfeits show tool marks and mismatched brushing.
- Insist on a Patek Philippe extract from the archives or a service record with a matching case and movement number.
- Price is the tell. Anything under six figures is not a 5304.
If you like the look but not the price
There are honest options. Skeleton dial watches from established brands exist well under five figures, and a few small independents sell real tourbillons at prices that are high but not seven figures. A vintage Patek in steel, bought from a dealer with paperwork, is a better use of the same money than a counterfeit that will not hold value, will not survive a service, and cannot be worn to a watch event without getting called out.