That's not true, I know several sources which sell their own custom blend of sustanon, and it's definetly exactly as advertised(example: sustanon400 consisting of 100prop/cyp/deca/enanthate). Also, getting test prop is really easy, it's dirt cheap and extremely easy to find. What are you talking about?
I think what you are trying to say is there isn't a UG that makes the exact combination of esters that is in pharmacy grade sustanon 250. If this is what you are saying - that is true. But, that does not mean there aren't plenty of UG's out there with killer test blends(ranging from test250 to test400) that are extremely similar, with the same results.