I also think it is realistic and practical to test for heavy metals and microbial contamination by anyone who wishes to spend the money.
I am far from convinced that it is realistic to expect market forces to make it an obligatory cost of doing business for UGL enterprises... at this point in time.
I would think that any reasonable consumer of black market injectable AAS would want these two tests added to the basic quantitative analysis of active ingredients as a minimum standard for harm reduction.