These discussions always make me smile. I believe the question is about 1)value and 2) personal taste.
Value: Are you getting what you are paying for? Do you wonder why one shoe costs $300 and the other $100? If there is $200 difference in quality and that is important to you, then go for it. If there is not that much difference in quality, then you are padding the pockets of the $300 shoe company.
Personal Taste: If it is important to you to own the original designer brand over a LEGAL knock-off, then I say go for it. If you would rather save your money on designer shoes to buy an original piece of artwork (for example) rather than a signed copy, then I say skip the designer shoes and go with the artwork.
If the quality of LEGAL knock-offs meet my standards and the price is right, I have NO problem whatsoever passing on the overpriced designer originals. I would rather use my money elsewhere and not pay more than I need to.
All a matter of personal preference, IMO. I would rather have original art than original shoes. Better investment, IMO.
I have a pair of Steven platform espadrilles and Steven platform pumps, both of which are CL knockoffs. The quality of the Steven brand I thought was excellent, and I saved hundreds of $$ over the originals. Do I tell people the are CL's? Nope! I proudly tell people if they ask that I am wearing poor girl knock-offs.