Hi reivilo,
Thanks for your feedback.
Both sites are the legit websites of Seeed. The io one is mainly for promotion and we’d suggest you place the order at www.seeedtudio.com.
As to the coupon, it’s already expired that’s why you couldn’t use it. And since it’s our belated response that made it impossible for you to use the coupon in time, our tech support team will email you directly & give you an extra coupon.
Thank you for your feedback. And please feel free to let us know if you have any other inputs. Thank you & have a happy week ahead!