Keep one thing in mind. It is likely that they have found several photos online, all of which would suit their purpose equally well. If this is the case, they have probably contacted the other photographers, too, and are most likely to go with the image from the photographer who is the easiest to deal with and does not want much money. Just be careful not to lose the sale because you are one of those who stipulate multiple conditions upon the sale, or want royalties of some sort.
I have lost a good number of sales because I asked a bit too much, and wanted to include some protective phrases in the agreement - things that would limit their use or give me more $ if they exceeded a certain number of units, etc. While insisting on these things may make good business sense in some cases, it will also lose you a good number of sales.
I have learned my lesson, and now I sell for a fraction of what I used to ask, and I allow the clients to use the image without many limitations at all. I close many more sales because of this easy approach, and net more dollars than I used to when I was paranoid and greedy.
"Your" and "you're" are different words with completely different meanings - please use the correct one.
"They're", "their", and "there" are different words with completely different meanings - please use the correct one.
"Fare" and "fair" are different words with completely different meanings - please use the correct one. The proper expression is "moot point", NOT "mute point".