Hello, how are you?
Hi, I want to sell these speakers. Thy're in great condition, never been opened in fact. I'm knocking $10 off the original price of $30. And, I'm good, thanks.
$30 seems a bit high, as I've seen quite a few go for less on eBay. Would you consider $10?
I really wouldn't, I think you can throw in a few more dollars for a new item.
Even considering this is what they are selling for online?
Yes, because then you have to pay for shipping. $13 and it's yours, that would be the shipping cost. 
I'll split the difference with you, and offer $11.50. If not, I'm sorry, but I think I'd be paying too much.
I'll do $11.50 just because I don't have the time to find another buyer, thanks.