Before the UK ban, I bought mephedrone from over there and was always happy. I recently bought a gram from mephedrone now and was wildly dissatisfied. For one thing, it is far too expensive. This is one of the few sources for mephedrone now that it is banned in the UK and this guy is taking advantage of his customers by jacking up the prices.
I got the product quickly and it was indeed a white powder as you would expect, but it burned rather than vaporized when I tried to smoke it, when I snorted a bit, it burned way worse than any mephedrone I have tried before, and when I swallowed a 200mg dose, it made my knees turn purple (and I have done much higher doses and never had this happen before). There is something definitely amiss with this guy's product.