I think you were trying to say such a sentence, "come and get your clothes from our store/ shop, they're a bargain." "To be a bargain" actually means that the items are offered at a lower price than normal thus providing customers with a valuable opportunity to get their stuff. I hope it helps!

There's nothing wrong with the grammar, but that's not a way a native would ever say it. Also, it's not clear what you mean to say in the second sentence.

Our clothes are on sale! Come take advantage of our low prices!

The sentence "Come to buy your clothes at our sale. Chances are valuable!" is a bit unclear and might not convey the intended message effectively. It seems there might be a slight disconnect between the two sentences. If you're trying to emphasize the value or benefits of shopping at your sale, you might want to rephrase it for clarity. For example: "Come and shop at our sale for great deals on clothes. Don't miss out on the valuable savings!" Remember to tailor your message to your target audience and the specific context of your sale.