Translation of Info

I need to write you one more sentence. This is what my teacher told me and the German language is so difficult. So please, as a last favor, would you please write the sentence for me in German?
The letter and the date are fine. Let me know how many people are interested. I cannot promise that it will work. The size however is OK. It is worth a trial, maybe even the ones with Spanish words.
The American (his name was Jeffrey) meant that this is the hour where usually the price of goods went down as the sellers were under pressure and did not want to return with the product.