Difficult to say, because I always paint in batches of 5 - 10 figures at a time, and spread out across several painting sessions, usually over the course of a week or two weeks, fitting the painting in when I can.
But I suppose if the figure was ready prepped, it would take around 1 - 2 hours to complete a figure from start to finish, depending a lot on how much detail was on that figure.
Put it this way... typically I paint only around 120 - 150 figures a year, so I'm certainly not prolific.
(I know some wargamers who paint 150 figures inside a couple of days...

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