I didn't realize that the MDA (Eagle) f/o rate hit TOS in year 8. The Group 4 rate for year 8 f/o is $67.86.
The latest pay table I can find on the ALPA site doesn't have Group 3 (which used to be the F-100) or Group 4 rates.
To sorta answer mweiss' question "Any sense of why they're paying the FO so substantially less than Captain?"
Don't know anything about express (or regional) pay rate evolution over the years, but mainline evolved from a system of each airplane having a capt base rate, to which was added a speed adjustment (faster paid more), a weight adjustment (heavier paid more), a night adjustment (or differential), etc. IIRC, the base rate progressed with longevity from 2nd to 12th year. (1st year - probation - was straight salary no matter what was flown). Once the captains hourly rate was determined, the f/o (and s/o, or flt engineer, when we had them) was a percentage of captains pay, with the percentage increasing from 2nd thru 12th years. Again, IIRC, f/o 2nd year was 50% up to 12th year at 66.66%. Of course, this was all reduced to a pay table for each a/c type and seat.
Apparently, at least the Eagle contract pays f/o's substantially less as a percentage of capt's pay than what mainline did (and does). It may have something to do with the fact that the regionals (or commuters, as they used to be called) were something of a training ground where a pilot would build time toward getting a job at a "major", but that's pure speculation on my part.
Jim