Upload & Sell: Off
Damn! Should I keep this or return it? Since it didn't cost much (around US$80), will it be a better idea to keep it for some outdoor video shoot?
If it cost $80, you either got a hell of a deal, the salesperson screwed up and gave you a much more expensive item, or you have been ripped off buying a counterfeit product.
I bought an 82mm variable ND heliopan filter last year for close to $400, which is a slim mount similar to the B+W xs pro filters. The B+W tent to be a bit cheaper than Heliopan. When I was looking for an alternative to Singh-ray for a vari-nd filter, heliopan, some fader filters and some Chinese knock-offs were the only options, so unless this filter is a new offering from B+w it may not actually be a b+w filter. If it is I'd keep it, because if it is an actual legit b+w xs pro vari-nd filter, you got one hell of a deal.
For my 16-35L, TSE 24L and 24-70L, I also picked up the 82mm b+w xs pro Kaiseman filter listed above . The cheapest I've seen that filter is aroun $120 from the Hong Kong retailer. Maxsaver.net