luai to the mob you want to track then execute the script.

do
local start = os.time()
mob.gold = 0
mob.silver = 0
 
local function do_it()
  local now = os.time()
  local dur = now-start
 
  local msg = string.format("Gold: %d, Silver: %d, Duration: %d", mob.gold, mob.silver, dur)
  say(msg)
  delay(4, do_it)
end
 
do_it()
end

To terminate, do cancel() from the mob's luai.

Before changeset 17f894157c3d

Mad Mulligan says 'Gold: 46, Silver: 5814, Duration: 120'
Appr 50 gold per min, 500 gold in 10 mins.

After changeset 17f894157c3d

Mad Mulligan says 'Gold: 460, Silver: 42965, Duration: 119'
Appr 450 gold per min, 4500 gold in 10 mins.