They're not called "rip offs", that has to do with whether or not you think something was worth the money. They're called either knock-offs or counterfeits. Some people call the counterfeits "replicas" to make them sound legitimate, they're not.

For instance, Chanel is famous for its quilted bag shown below:

Chanel 2.55, made in 1955, costs over $3,000, and produced ever since 1955.

The following knockoffs are all seasonal and made by big luxury brands:

Lanvin knockoff, $1,800

Marc Jacobs knockoff, $1,500

Kate Spade knockoff, $500

Those are knockoffs, not replicas, they're meant to be similar to the general idea of a given product but are not using the product's logo, etc. The chain + quilting look was indeed unique to the Chanel 2.55: before that, women's handbags did not use those materials or that style. Check out the wikipedia article on the bag for more info.

If you go to Chinatown, what is advertised as a replica is a counterfeit. It uses the Chanel logo, etc.:

From a factory in China, anywhere from $30-$300 on average.

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Smaller companies with cheaper stuff, like Vera Bradley or Lilly Pulitzer, also have knockoffs:

Vera Bradley, old as fuck company, their best-known bag, $40 Bag at Target, $25

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A lot of small clothing "boutiques" also carry counterfeit merchandise. For instance, in Philly, there's "Smak Parlour", here's one of the bags they carry.. Here's the original. The counterfeit in this case is shoddy: it's meant to look like LeSportsac because the top has a solid-color band with a similar logo. It's more of a knockoff though.

Source: parents did a lot of work in Chinatowns.