Firstly, it's not illegal. And if it were, TOR Browser + Prepaid card + Anonymous dead drop. Elementary, Brosquire.
Secondly, it's not my money, and maybe this thread can be helpful since there is so little info on the web about this 'Test-600x' stuff.
They did ship quickly, so kudos to them there. They should list the ingredients out there openly.. So I guess this thread can do that, since it seems to be the only damn one on the intertoobs which does so.