I'm selling each countdown coin for about 50TBT.
I don't think you have enough to buy all of mine. With the amount that I see in your profile, you would be able to afford 5 countdown coins, which is currently not enough to buy anything from the shop.
I know there are some people trying to buy the gradient star fragments for about 1000TBT. There was someone recently in one of the other threads who sold their 72 coins for 3K.
You can try to post a thread asking if anyone is willing to sell you their countdown coins at the price your offering. But I will need to politely decline your offer.
Thank you for your interest though.