well... any batch/brand will last for no more than a week in each city, so the chances that you'll get hold of something from years ago is... ZERO (unless you know someone who purposely stock piled them). To make things worse, only about 1/3 of what's sold as X is the real thing (meaning MDMA, MDE, MDA and nothing else). That used to be 2/3 just a couple of years ago...
The only way to get good stuff, imho, is to get it from a very thorough and dependable source, look 'em up on pillreports AND test them yourself. It's that bad out there right now.
And, you get what you pay for. If you're paying $12, chances are that you get crap.