Kitten has sores and hair loss around neck

Help! When I got my kitten you could feel these weird scabs under his fur around his neck. I asked my aunt, whom I got the cat from, about it, and she said it was from the mother playing too rough with him. I assumed they'd go away after a while. Then I noticed they've started ozzing and bleeding slightly. Now his neck is almost completely bald and his sores are even bigger. He is 16 weeks old. I can't afford to take him to a vet as of right now. He doesn't seem to be in any pain. He just keeps licking and scratching them. I'm wondering if it's from his sister playing too rough or maybe all his scratching and licking. I need some advice! Will it go away or should I take him to a vet as soon as I can afford it? I'm worried that they'll do a bunch of tests and stuff and say it's nothing to worry about, but then I'd have some ridiculous vet bill that I can't afford because I'm just a student. I don't want my little boy to get worse or be in pain, so I'll do whatever it takes to get him help if you guys believe that he needs it.

I believe that he does need to see a vet.  Those sores look very uncomfortable, and could get infected.

Has he been neutered and vaccinated?

The sores look actively infected.  He probably needs an antibiotic that's good on skin like Simplicef, and the underlying cause needs to be addressed too.  Maybe someone close to you can help you with the ost, which may be modest if treated soon, and much more expensive if treated later.  Your cat is in distress, possibly in pain.