I don't believe the flat pay scale is accurate. If I remember correctly from those who work there, the FO pay goes up to $18 or $19 second year, and then roughly $1 more per year after that. I think the captain pay follows the same trend.
But no one has spent much more than a year as an FO there for a pretty long time. A lot of FO's leave for other regionals, and the rest upgrade in about a year; at least that's what's been happening lately.