Seibertron is claiming to have official images sent to them by Universal Studios of a grey redeco SS-34 Leader TF3 Megatron, to be an upcoming exclusive of theirs. Since there is no link to a product page, or to a Universal Press Release, I'll leave it as a rumour until it can be confirmed from an official source.
If it is true, it will be expensive... based on how much they charge for Deluxe exclusives (US$30, which is double their original retail price over there). A Leader class exclusive could be as much as US$100 (about AU$155, plus shipping if they list them on their Florida online store).