5. We'd like to know what you can offer as well as your sales conditions.
我们想了解你们能供应什么，以及你们的销售条件。
还能这样说：
We want to know your offer and the sales condition.
We'd like to inquire about the offer and sales condition.
应用解析：
bring-and-buy sale 义卖；
for/on sale 待售，出售；上市

6. How much do you charge for the goods per unit?
你们每件要价多少呢？
还能这样说：
How much have you quoted per unit of the goods?
What's the price of per unit?
应用解析：
under the charge of 由……看管，由……负责；
charge for trouble 手续费；
take charge of 负责，看管

7. How soon can you have your product ready?
你们多久才可以把产品准备好呢？
还能这样说：
How long does it usually take you to make delivery?
When will it be delivered to me?
应用解析：
Ready, present, fire!
（军）预备，瞄准，放！

8. Please inform us the quantity that can be supplied from stock.
请告知可供现货的数量。
还能这样说：
Can you tell us about the quantity you can provide?
I'd like to know the quantity you can supply.
应用解析：
stocks and stones 无生命之物；木石；迟钝的人，死气沉沉的人