New vs used laptops for college which one?

So I'm looking to buy for myself a laptop for college, I do plan do play a few games on it (Civilization 5 or 6, Shogun 2, maybe even Stellaris) mostly while I travel in train from and to college and I already have a decent gaming PC so please don't tell me to save some money buy a PC instead. My best choices for my budget of ~350 to 420 euros are :
HP ProBook 640 G2
14" LED 1366x768 used 400 euros
Intel Core i5-6200 2.3Ghz
8Gb DDR4
500Gb HDD

Dell Latitude E5450 used 370 euros
14" LED Full-HD IPS 1920x1080px
Intel Core i5-5300u 2.3Ghz
8Gb DDR3
128Gb SSD PCIe

Acer E5-575G 15.6" 1920 x 1080 new 380 euros
Ekran - 14" LED Full-HD IPS 1920x1080 used 370 euros
Intel Core i5-5300u 2.3Ghz
8Gb DDR3
128Gb SSD PCIe
nVidia GeForce 940MX 2GB

Both used laptops are in excellent condition seller is my neighbor so he let me test those two but I can´t decide between the three.
Now the main usage will be MS Office, occasional gaming as stated above, watching Youtube and movies and maybe Math-lab but I have a solid PC for that. Portability is a great plus and I like business class laptops for their quality but the Acer has a dedicated GPU and a decent one for that price. Which one should I pick and why?
I´m also open to suggestions.