I am amazed at how so many people here understand so little about the circumstances going on here.
Being a uni student does NOT make you poor, I knew a few of my fellow students who made more than 20k a year at uni before graduation, heck, I was past that when I was in 3rd year. With the right combination of grants and living arrangements, even as a freshman, I could support myself AND have money to blow on video games and systems.
As another pointed out, we don't know if he is the biological father, he could be married/in a relationship with somebody a couple years older than him, and he's seeking to bond with the kid (who he's come to accept as 'his', regardless of actual parentage).
4 year olds are perfectly capable of playing video games. I played the LEGO games with a 3 year old and it wasn't... awful. Took some steering, but the kid had TONS of fun, and every week when he'd visit he wanted to play Star Wars LEGO with his Uncle. This was a few years ago when the franchise was new. Now, I bet he doesn't even remember who I am, but at the time, he certainly did. A 4 year old would be even more capable.
The victim blame here is just disgusting. As far as his decision went... he had the money, and he made a risk/rewards assessment, and hoped that since the vendor had a good reputation that it was legit. Regardless that he was... leery of the purchase since the term 'picture' was in there, there is obvious intent to deceive on the part of the seller. That is a CRIME. The seller is a CRIMINAL, and should be considering themselves fortunate that Paypal and eBay are not pressing charges against them.