Hi, We would like to buy your product with number XXX. But first we would like to buy one sample in order to check it. If we like it we will buy 50 pieces. We would appreciate it if you could inform us about the technical specifications and the price and if you could send us some detailed pictures of it.
Made some small edits to make the text more English in tone (eg 'we want' (sounds very demanding and not very polite) to 'we would like' (more commonly used in this type of situation).
Original translation:
Hi,
We want to buy your product with the number XXX. But first we want to buy for checking one sample. If we like it we will buy 50 pieces.
We will appreciate it if you inform us about technical specifications and the price and if you send us some detailed pictures of it.
But first we would like to buy one sample in order to check it. --> However, first we are going to buy one piece and check it.
We will appreciate it if you inform us about technical specifications and the price and if you send us some detailed pictures of it. --> We would appreciate it if you could inform us about the technical specifications, the tender and detailed pictures belong to the product.