They started equal. Ham gained $1600 and Jam lost $750, so Ham is now $1600 + $750 = $2350 ahead. Ham now = 2 units, Jam now = 1 unit, so that 1-unit gap is $2350.
Plain numbers are given; italic underlined numbers are worked out.
Each of them had $3100 at first.
Check: Ham $3100+$1600=$4700, Jam $3100−$750=$2350, and $4700 = 2 × $2350. ✓