Yes.
I bought a Bininiu from Amazon (in UK) when my SRAM battery died.
.
I needed a battery next day to go out a group ride in two days time, so I went for it.
About 1/2 price of a SRAM original. Worked well for me, so far.
On the bright side, SRAM honoured the warranty a couple of weeks...
Just a possibly controversial thought - if "it's lasted longer than the original one" and "was 30% cheaper", assuming it worked OK too, what's the actual problem in this specific case? (apart from the obvious issue that fakery is illegal, and usually fakes are poor quality), I'd simply ask...