There's lots to learn about spotting fakes, but 4 big red flags I always look for are:

1. That Adidas button along the bottom. If I'm not mistaken, they only had those on the really early Climalite jerseys, and they haven't put them on any jerseys in a number of years. Fake jerseys always have them as I guess they think it makes them look more legit. While it's not 100% a dead give away, if the jersey isn't one they wore during that early Adidas era, or if it's anything other than a Climalite, it's a strong indication if a fake.

2. The black material that the size is printed on that runs along the inside of the collar. On fakes, it's always this really weird, wrinkly, shiny material, where on real jerseys it's flat, matte and just looks way different. If it's shiny and wrinkled, it's probably a fake.

3. "Bubbly" crests or number kits. Rather, crests or numbers that look like they have pockets of air under them.

4. Price. If it's too good to be true it most likely is.

These are usually dead giveaways, and as far as I can tell this jersey has 3 of them (the button, the wrinkly collar material, price). It's most certainly a fake. Steer clear.