ご返信頂きありがとうございます。
もしよろしければ、商品代金の$135.6を返金しますので、
商品は返品されずにそのままお受け取り頂けないでしょうか。
おそらく商品は開封されていると思いますし、
返送にかかる送料に加え、関税も私が負担するとなりますと、
こちらとしてはその方がありがたいです。
また、あなたの手間も減らすことができます。
もしよろしければ、すぐに全額返金致します。
お手数をおかけし大変申し訳ございません。
ご検討の程よろしくお願いいたします。
If you don't mind, will you keep the product without returning it to me while I can refund the money for the product?
I assume you may have already opened the product. Also given that I would be responsible for a return shipping cost and customs fee, it would be much better for me.
Also, it would save the trouble for you.
If you like, I can make a full refund.
I apologize for inconvenience this has caused.
I would appreciate if you could consider it.
I'll refund $135.6 of the products amount, so please keep the product on your side, if you can.
You maybe open the product, and the shipping fee for return and customs charges on me so that it would be better for me not to return.
Also, it could be reducing your effort on this.
If you agree with my idea, I'll refund all amount immediately.
I'm very sorry for taking your time on this.
Thank you very much for considering of my proposal in advance.
I would like to give you a full refund of $135.6.
Also, please keep the products if it is okay for you.
I assume that you already open the package
and it will be better for me if you can keep it
considering delivery fees and customs for returning the products.
I do not want to bother you either.
If it is okay for you, I will give you a full refund right away.
I am sorry for causing such a trouble.
Thank you for your understanding.
I am looking forward to hearing back from you,
2行目のthe moneyを$135.6に変更して訂正します。すみませんでした。