Purple Haze is not to be found. You can still bring it back into the gene pool, if you're willing to grow out 1000 beans. The purple haze pheno is one that shows up in the Original Haze, and the odds of it showing up are 1:1000. It's no longer around, because while it was pretty, and technically a true purple - one who's colors are not brought about by temperature fluctuations - the other valued aspects of marijuana - flavor, smell, high - were found to be lacking in this phenotype. So people stopped growing it.

Weed is not 100x more potent now than it was previously. It has been proven you cannot increase the potency of a plant more than either one of it's parents. The potential power of a plant is a genetic imprint that cannot be raised. Lets say you have a Nothern Lights plant that you maxed out at 22% THC. Say you've grown a Haze female that hit 23% THC. You cannot cross a male and female from these breeds (max THC around 22-23%) and get a plant that will hit 30% THC. Weed seems more powerful now than previous, because previously, most growers were chucking seeds in the ground, watering them like any ol' plant, and letting Ma Nature take care of the rest. Now we have great growing resources, a lot more equipment and information to make indoor grows successful, and we have unlocked more of the plants' potential than had been do previously. So the plant didn't get stronger, our methods just got better.