Hey Vlad,
Not trying to troll your post, but you should keep your $300 and save a bit more. You may find someone that will sell an old, beat-up kit for that amount, but realistically, a lot of us end up spending $1000 - $1200 or so, once you have bought a kit, soft parts, and the tools and materials you need.
Just trying to help, and good luck on your endeavor. I would love to be wrong and you find a kit for that amount. I just don't think that number is realistic.