I just bought an RC-402 for my Tascam BR-20. Got it for a really great price, but not too good to be true. It looks to be in terrific condition, but the caveat is: It's coming from the UAE. That's a long way from our shores. Hopefully it will eventually arrive in an "as advertised" condition.
Price was waay, waay better than the rip-off prices for a similar item being sold via US sellers. Only hope I'm not the victim of the ultimate rip-off.