ご提案ありがとう。
ただ、$350では利益がでません。
さらなる値引きを検討してくれませんか?
数量を増やしても構いません。
ご連絡お待ちしております。
Thank you for your proffer.
However, I can't make profit with $350.
I would appreciate if you can generously consider a bigger discount.
I could purchase more amount.
Looking forward to your reply.