I would say it would be better to sell a knock-off product than to create your own design, even though it would be easier to say if I knew precisely to what you were referring. A basic fact in marketing is that you can not manufacture demand. What this means is that it is easier to find a need or demand and then fill it with a product than it is to make a product that you feel like making and then try to create a demand for it. People basically want what they want, and you can't make them want something just because you've created a product.

Based upon that important business principle, if there is already a high demand for the product that you are thinking of creating a knock-off for, and you can create it fairly cheaply, than you are better off just filling that demand that already exists. If you were to make your own designs, the same amount or degree of demand may not be there. Your design may be just as good, but if there isn't a current demand for it, then you would be better off pursuing the knock-offs, as you call them.

You'd better hope the product you're thinking of knocking off isn't from a brand owned by LVMH. I wouldn't recommend scamming the world's most litigious luxury goods retailer!

While I guess the ethical implications would have to be looked at in detail, I also happen to think that knocking off other another company's product just isn't very classy. Reputation is everything, and it's just not something I'd want to be known for. Sure, you may make some money, but you may also be "branded" in a certain undesirable way by people who aren't happy with your behavior.

Personally, I would rather have people buy my product for what it actually is; not for its extreme similarity to another item I didn't create. I'd also rather sell products that are unique and can't be purchased other places.

How about this: Start your shop by selling knock offs then, after you have developed a customer base, begin to integrate your own designs into the shop. After you've already gotten customers, and they are happy with the items that you are selling, they will be much more receptive about looking a bit further than the costume products that you are currently selling.

Many customers know a good thing when they see it so if you can get one or two of them to see your new innovative designs, you may be the next great thing.

Never short sell yourself. Everyone has something they want to love to do, and they should all go for it. To begin with, however, get your shop or internet shop off the ground, sell what they know, and then begin to advertise and market your own designs as the company begins to profit.