初めての取引ですので、高額な取引は、お互いに不安です。
最初に一つだけ注文して、無事に届いたら、残りの商品を注文されてはいかですか。
This is your first ever purchase from me. A transaction in a large sum would make us both nervous. Why don't you place an order just for one item, and if you're satisfied with the results, place the rest of your order? Just my two cents.