Yes.
Gen 4 and 5 games are way too valuable to be selling for under $15, and there's no way a same person would have hundreds of them to sell, esp for that cheap. Where I live, they go as high as $150 (gen 5).
These are 100% without a doubt, repro cartridges.
Here's some warning signs when buying cartridges:
- Does it look new? Any wear? If it's lacking wear, it's probably fake. They don't make new old games.
- Is the sticker slanted? If yes, it was hand-put on. This doesn't always mean it's fake, but it definitely means it's been tampered somehow.
- The price. Gen 4 and 5 games are valuable, typically pricey.
- The Quantity. If there's more than 10 for sale by the seller, assume it's fake.
- If the seller claims it's new. Gen 4 and 5 games are too old to be new. If you find an unopened box copy, chances are it'll be for sale in the 100's
Here's some tips when buying old games:
- Buy local. This way, you can test the game out to make sure it works.
- Know the value of the game. Knowing the game's value in your area can help you know if you have a deal, or are about to be ripped off.
- Signs of "aged" cartridges are good. Slight scratches and tear on it proves that it's been through a long, working life, make sure it works of course, but imperfections are a good thing when looking for authentic cartridges.
- Seller's history. If you're buying online, make sure the seller has a good reputation, and isn't selling millions of the same game.
In conclusion, if you think it's fake, it probably is.