Unless I'm mistaken, the ebay case had nothing to do with the fact that these were "grey market" goods, and everything to do with the fact that ebay did not police the sale of counterfeit goods. The sale of grey market merchandise is and has been (for a looong time) perfectly legal.
I'm in the perfume business, so I have first hand knowledge. I have a perfume store and website and we sell "grey market" merchandise. All name brands. We sell NOTHING counterfeit (and would never). I believe someone mentioning case law from about thirty or so years ago, which opened up the grey market, as follows (in a nutshell).
The perfume companies (Gucci, Dior, Chanel, etc, etc, etc), tried suing a retailer of grey market perfumes, and lost, because, most of these goods are obtained legally (albeit often times going against the perfume companies' contracts with duty free distributors and other distributors oversees). In other words, Gucci sells to Duty Free ABC and in their contract, it states that these items can ONLY be sold at retail. Duty Free ABC disregards this and begins wholesaling/exporting this merchandise to the US. While it might be against their agreement with Gucci, it wasn't against the law. Gucci was within their rights to sue Duty Free ABC for damages and was also within their rights to stop selling to them but they could do NOTHING against the people buying and reselling the items. Right of first sale. I bought it legally and can sell it now as well.