While Automatico sums it up very well, the quality of the aftermarket cases do vary beyond the engravings, very much so. There's a valid reason why the higher end suppliers charges what they charge and mid range suppliers charge what they do.
There are details on the higher end cases that are for the most part, spot on and they require very little modding, if any at all.
While the "lower" end, and by lower I mean $400-500 range, lacks in some of those details and like their predecessors, the infamous "MBW", require a good amount of modding in order to achieve a "gen" look.
Even the hh 5514 case, as great as it is, and as unfortunate as it was to be halted, requires some modding in order to get the right look and feel.
I have owned a good amount of these variations as have many members on this board and they will all attest to the above.
If its something you want to do, and can avoid the law, go for it. But also, like Automatico said, that initial production is gonna be costly to produce. Personally, I think you would do better to set up a relationship with a supplier from China or Vietnam, order wholesale, and collect a premium for supplying cases in the EU.
It's a better bet for you in a lot of ways. Good luck