这样的客户我该怎么谈判？

今天收到一封邮件，让我不知如何下手，请各位大神帮忙指点一下，
邮件内容如下：

Hello Niecey!

We got your new price list. Thank you.

Sorry to tell, but we don't need new supplier of LED bulbs as we have
old and reelable suppliers from China and Korea. We work with them for
many years and we know we can trust their quality.

But we can start to sell your bulbs too if you accept our offer:
1) You send us any of your bulbs, any quantity. You can send 1 pc
each, or 10 pcs each. Don't sent us bulbs that will not work for 1
year. I'm sure you know your best quality bulbs. We need them only.
2) We will pay for shipping when we receive goods.
3) We will pay for goods within 1 month after we receive them.

We work same way with our old suppliers. They offer us 1 month payment
delay because they know who we are and they know that our shop is old
and very popular. In fact our on-line shop was first in Russia who
start to sell car led bulbs in 2007.

We can sell big quantity and you will get payments every month.

If your bulb are good we both get good profit. If your bulbs are bad
and they will not work for 1 year than we will stop our cooperation.
We don't sell non reliable bulbs because people trust our quality. We
work on this reputation for many year and we don't want to lose it.

You may think that this is a risky for you, that's why I'm telling you
- you can start with any quantity. This is same as to send free
samples.

I think after you get 1-2 payments you will have more trust to us. I
will give you contacts of our transport agent in Beijing or Shenzhen
once we get agreement.

I believe you can accept our offer if you want stable sales and
Russian market.

Thank you.

Bulatov Dmitriy
Head of Purchasing Dept.
NeTuning.ru

查了一下网站的whois信息，跟他说的基本吻合

[attach]3325[/attach]

我们公司所有的单都是收全款然后再出货的，样品单我可以申请免费的，但是后面出货的基本上是不可能1个月过后再付款。

最近一直在看毅冰的课程，说我们要抓住一切可以的机会争取合作。
俄罗斯市场，我们公司的产品卖的还可以，虽然去年卢布贬值有很大的影响，但是优质的客户还是在继续做。
各位米粉，给我支支招，谢谢~~