I put in the value as what I paid for it the month before I sent it in. (Although, I thought it was $350).
I'm always unsure what to put in on a book's value when I send it in because I feel that RAW's aren't worth as much as graded (so me declaring that it was worth just as much as a graded 7.0 seems like a bad idea). Also, I thought that the smudge/stain had a chance to send it back with a purple label, or with a hidden defect that knocks it way under what I expected. So, I figured the best thing to do was just put in my purchase price.
While I would have "won out" on this one if it came back as a 7.0+ blue label, I don't see CGC refunding my money if I value something too high that comes back as a green or purple label. Again, I typically just put in my purchase price, and try not to get too fancy.
It DID say "CGC credit" in the email...but it's great that it no longer the case.