His annual sale is in November. Its by invitation only, and unless you have a private invite from Sid himself, its reserved for locals (Vancouver) only.
Its Sid's way of giving back to the community, that supported him from the beginning.
The blocks he sells at this annual event are called "Red Backs" aka "Seconds". You will see them on ebay from time to time. The backs are painted in Red. Even though these blocks are seconds, they are very close to mint condition. I have seen many red backs, and rarely can I tell the difference.