It is based on a really bad appraisal algorithm that is rarely right, I would price the domain yourself and not pay much attention to it unless it is telling you to go higher.
It just suggested a $478 BIN on a triple premium LLL.org that is also a first name and a palindrome, which I could easily wholesale for $1,500+ in a day. In this case it was the exact midpoint of a price range from $239 - $717 which isn't at all accurate to begin with.
Other than one 4.CN fluke the price they suggested would be the lowest triple premium LLL.org sale in more than two years by a margin of several hundred dollars, and easily one half to one third of what they usually sell for. And liquid domains are easier to "appraise" accurately as they are more predictable, I think the keyword domains would be even harder to make good suggestions for.
In fairness, this lack of accuracy is not unique to GoDaddy though, Sedo's are bad too (although slightly better in my experience). Automated price suggestions are extremely difficult to get right, perhaps even impossible.