Best advice I can give anyone... And I've been in this business a long time but only on the Web for a short time... Advice would be to order small amounts from various dealers and either have it tested or use it yourself and do blood work.
There is 100% no quick way to get ahead in the aas business. There are so many fakes and people trying to rip you off that you just have to understand that your going to lose some money along the way.
I used to grow alot of pot in my day, the rule of thumb when growing outdoors was thst 20% of your plants were going to die, get stolen or just not grow.... With aas, 20 to 30% of your deals are going to be shit, just as long as you understand this going in, you'll be fine.