If there is some sort of receipt or proof or purchase from Ploom I would be very interested. You can get these on alibaba/aliexpress for super cheap and the clones are VERY well made, it's hard to tell the difference.
I have used certain clones, some are great but even then, I think it is worth paying extra for ploom's 10 year warranty. One of the clones I used, after cleaning it it simply stopped functioning, even though I followed the careful instructions of cleaning the device just like I do with my authentic unit.