That's definitely a scam.
1) loves your fair price...
2) willing to pay full price (no one does this, they always negotiate)
3) service member, so you feel like you want to help
4) on active duty, deployed, whatever, so they can't come themself, a family member will come
5) the final thing that nails it for me is usually the email comes within 30 minutes after I post it.
I sell ALOT on craigslist, I've seen these time and time again.
I just delete them when they come.