Looks like there's a pretty popular vendor for amphetamine sulfate on Nucleus - Rangoon. It's pretty spendy - $70 per gram (!!) so I'm inclined to think its more "pure" than all the other bunk floating around. But 99% of amphetamine is cut, so...
Anyone send in a sample to extasydata.org, or have recently tried his stuff? Experiences? Some of the older reviews look like shilling so idk.
I'm thinking of getting this stuff tested out of curiosity. Although at his prices, it might just be cheaper to buy amph paste for $20/g and purify it with an acetone wash...
FWIW, I just did an acetone wash on FredTheBaker's speed powder, and received 99% of the product back. (Did 24g total. 1g then, 5g at a time with 10mL dry acetone per Gram of powder) If there was any weight lost between batches, it was +/- 10mg
Now, the 'cleaned' product still burns when insufflated, and it still smells too much like chemicals to me (Compared to SuperSpeedBros which is A+) But for the price I paid ($155 for 25g's vs $40-90/G domestic) I would much rather go with the least expensive, unless you don't mind spending the money for top notch quality amp.