How can a 12/13 yr old make money?

Hi, I'm 12 years old and I'm turning 13 in three months and I really want to come up with $300. I have gotten into Minecraft PVP and I want an upgrade from my laptop because I have to go on optifine to mega low settings for a decent frame rate. So I want to save up for a $300 APU build. It's becoming fall right now and I want to have it all saved up by the end of winter. I know I'm able to rake leaves and shovel snow and I'm already planning on it but I need more ideas of what to do. Please leave a lot of suggestions because I'm willing to do all. Keep in mind I'm not the wealthiest so my parents cant give me allowance but if there are any ideas for what I can do to work for them, they could pay me. (Btw no, I don't want to buy a $150 50gb xbox 360, its not the same. I only like Minecraft on pc.)

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