Off hand I'd say that if you're expecting to buy a Ruby's costume and have it look almost exactly like you walked right off the set you're almost certainly going to be greatly disappointed. You might be able to buy a deluxe, or whatever they call their top of the line costumes, and mod it to be more screen accurate but it will almost certainly not be so right out of the box. I'd check eBay and see what the usual overseas cosplay costume sites have to offer, they can't be any worse than a Ruby's and it will probably be a lot cheaper too.
If you're just looking for a basic Halloween costume to wear to a party and forget about it then you're fine buying a Ruby's. The cheaper ones will just screen printed details for the most part with maybe a few raised details like musculature using foam sewn into the costume. The higher end (read more expensive) ones will have more detail with more raised pieces and less screen printing but these will still be far short of a con worthy costume.
