タビオは英語の使い方に注意した方が良い。

I went into Tabio in Coredo the other day to get a pair of socks. It was during the clearance sale, and I was excited because I thought I might get a good deal on the socks that I wanted.

• clearance sale 〔商品の〕クリアランスセール、在庫一掃［処分・整理］セール、見切り売り

Unfortunately, there was this sign on the rack which held the socks that I wanted to buy.

✖ These are not at sale.
◯ These are not on sale.

We never say "at sale". You can say "for sale", meaning "available for purchase". Actually, it would have been really funny if the sign had said:

• These are not for sale. = We will not sell you these socks. You cannot buy them.
• for sale 売るために (definition from Eijiro on the Web)

At least they didn't make that mistake. However, their English sign makes no sense.

They wanted to say that even though it was the clearance sale, some items did not have a discount. That included the socks that I wanted to buy.

Tabio had a documentary on TV the other day in which they were bragging about how international they had become. They were boasting that the quality of their socks was being recognized around the world. If their English were better, maybe they would get even more recognition. They should be as careful about their English as they are about their socks!