Mazda6 shaking occasionally

Please withhold comments only saying I'm stupid for buying the car. If you're going to do so, please at least give an opinion or advice.

I just bought a 2006 Mazda 6 for $1900. It has a crack in the windshield and a few dents, a shitty interior, and 208,000 miles, so I don't think the price was suspiciously low. We drove it off the lot for about 10 minutes, it seemed just fine. I couldn't take it to a mechanic before I bought it, because I was short on time and it was an hour away. I needed the car ASAP. When I first drove it, I didn't realize it had a manual mode, so I had it in first gear and redlined a lil bit before I realized what was up. Regardless, I drove it an hour home, and it was just fine. I drove it about an hour after that, and I noticed that at a certain point on the gas pedal, sometimes it will kind of shake the car. It doesn't sound good, it doesn't smell good. The check engine light is flashing, which I'm aware means something severe is up.

If I push on the gas and it does that, I'll let go, and it will go away. Alternatively, I can push the pedal down a little more and it will go away. The check engine light turns off after about 10 minutes, and the problem fades. It comes and goes.

No problems while idling or very low speeds, but I've only had the car for the day.

I'm taking it to a mechanic tomorrow. But I'd like to know your guys' opinion, how fucked is this car, and how much am I going to have to spend to fix it? Is it worth it?

If you need anymore info please ask.

Error codes read:

P0306 Cylinder 6 Misfire Detected

P0306 Cylinder 6 Misfire Detected