>>2553316well, think of it this way.
if you play and enjoy all three games, you'll spend 180 enjoyable hours.
if you start with witcher 1 and you don't like it, you'll waste 5-6 hours of your time and pay 5 eur or however much it costs
if you start with witcher 3 and you don't like it, you'll waste 5-6 hours of your time and pay 20 eur