We offer the
TC80i through the Shack Electronics Store and all three vendors are authorized dealers. The Amazon vendor offers free shipping as well. Those appear to be the lowest authorized prices available. Same with the
CSI A6... the Amazon link has free shipping.
On the CSI A6... I believe the first vendor may not be authorized, but OneCall, Amazon and J&R are authorized. I generally prefer Amazon since they offer a 30 day money back guarantee and free shipping.