This can be applied to other branded/logo motorcycle jacket such as MV Agusta, Yamaha, BMW, etc.

Some Ducati motorycle leather jacket can be had on eBay for as little as $350, while some are much more expensive at $1,000.

Why is that?

The more expensive Ducati leather jacket are made by Dainese. Which is a premium, one of the best motorcycle leather manufacturer in Italy. Dainese is a high quality motorcycle leather manufacturer with product that have been proven in MotoGP. Worn by riders such as Valentino Rossi.

Cheaper Ducati leather jackets are made by generic manufactures in China. These manufactuerers can make any style/color jackets with any logos. Theya lso don't advertistise the jackets as Dainese, just Ducati or any other motorcycle brand.

What is the difference?

The cheaper versions advertise by their motorycle brand such as Ducati, while the more expensive jackets advertise by the jacket manufacturer such as Dainese, Alpinestar, etc.

Quality of the leather is hard to determine, while manufacture such as Dainese or Alpinestar have conducted extensive tests on the road and track with a high degree of quality control. Jackets from generic manufacturers can not be expected to conduct the same level of quality control.

Leather are thinner with jackets from a generic manufacturer compares to Dainese.

Safety

How much is your body parts worth, are they worth the $500 you saved on jackets when you fall off the bike at 100km/h?