The short answer

A replica IW545120 is a copy of an IWC Portuguese-family reference, and the copies on the market run from a $90 quartz knockoff to a $400 to $600 automatic that gets the case shape, dial printing, and hands close to the original. No replica is identical to a real IWC. The good ones read correctly on a wrist from a few feet away. None of them fool a watchmaker, none hold value, and importing a counterfeit into the United States is illegal. If you want one anyway, the decision comes down to three things: which workshop built it, which movement is inside, and whether the QC photos match the listing.

Learn the real reference before you shop

Pull the spec sheet for IW545120 from IWC and write down four numbers: case diameter, case thickness, lug width, and caliber. The 5451 references sit in the Portuguese line, which means applied Arabic numerals, a railroad minute track, leaf-shaped hands, a thin polished bezel, and a dial with a lot of empty space. Empty space is unforgiving. A crooked numeral or a date window shifted half a millimeter is obvious on a clean dress dial in a way it never is on a busy chronograph, which is why this reference is a harder copy than a dive watch.

The three tiers you will see

  • Under $100. Quartz or a rough automatic, stamped case, mineral glass, printed markers instead of applied. It reads as a watch in the Portuguese style, not as the watch.
  • $150 to $300. Automatic movement, sapphire, applied numerals, decent case finish. Most casual buyers land here, and this is where flaws show if you look: soft dial printing, wrong date font, gritty crown.
  • $350 and up. Better case machining, closer dial proportions, decorated movements, sometimes a hand-wound caliber that winds like the original. Still a replica. Still not a five-figure watch.

What to check in QC photos

Ask for photos on a plain background, plus a short video with the watch running. Then go down this list:

  • Numerals: applied or printed, level, and aligned with the minute track.
  • Hands: length and shape. Leaf hands come out too wide or too flat on cheaper tiers.
  • Date window, if the reference has one: position, font, and flush with the dial.
  • Case: lug bevels, brushed versus polished surfaces, crown engraving, thickness against the spec you wrote down.
  • Crystal: single or double anti-reflective coating. A milky blue haze points to no coating at all.
  • Caseback engraving: depth and letterforms, not just the logo.
  • Movement shot: rotor decoration, jewel count, and whether it matches what the listing promised.

Movements

Most copies run an Asian automatic based on the ETA 2824 or a Miyota design. They keep time well enough for daily wear and they are cheap to replace, which matters because servicing one costs more than the watch. A hand-wound copy is the simpler build: fewer parts, no rotor to fake, and a winding feel that can sit closer to the original. If a seller will not name the movement, assume it is the cheapest one in the catalog. Ask whether the case takes standard parts, because a stripped crown thread on a one-off case means the watch is finished.

Money, shipping, and customs

Pay with a method that can be disputed, and read the seller's policy on seizures. Counterfeit goods are illegal to import into the United States, and Customs and Border Protection seizes and destroys them. Sellers usually offer a reship, not a refund, and a reship can fail twice. Treat the money as gone the moment you send it. Debit cards, bank transfers, and gift cards leave you with nothing to argue with.

The parts nobody mentions at checkout

  • No warranty and no factory service. Many independent watchmakers will not work on a counterfeit at all.
  • Water resistance claims are marketing. Do not swim with it.
  • Resale is close to zero. There is no second-hand market for a used copy at anything near what you paid.
  • Lume is weak and fades within a year or two.
  • Plating on gold-tone versions wears through at the lugs and crown.

Bottom line

Buy the tier that matches what you want. If you want a watch that looks like an IWC Portuguese on your wrist and you accept that it is a copy, the $200 to $400 automatic range is the only one worth your money. If you want something you can still service in ten years, pass on all of it and put the cash toward a used dress watch from a brand with a real service network.