You've already given a -1 on his feedback even though the mods haven't weighed in. Tis not the way the system works here.
Yes, I see a deal here but from his "I'll take it" to now is less than 72 hours.
Not everyone is on the net constantly. Can you guarantee that he received the message with your phone number? Did he say he was backing out?
You sent him a message barely 12 hours previous and he hasn't responded? People do have other things that go on in life. And yes, I've seen that he has logged on here today.
My $0.02, give it a little time for him to get back to you.