A $300 Fender acoustic is going to frustrate a beginner. They're crap, with low QC. A beginner would be better off getting a playable electric or waiting until they can spend around $1500-$2k and get themselves a playable acoustic.
I agree that I probably wouldn't go with Fender low-end (they are crap), but there's plenty of good bargains in the 300-400 range that won't frustrate a beginner. There's probably 4 or 5 Epiphone, Seagull, Alvarez or Ibanez low/mid-range guitars hanging up at your local pawn/small guitar shop right now. Even some old Harmonys, Kays or Silvertones can work out real well, depending on the guitar. My favorite acoustic to play right now is my '53 Kay arch top that I picked up for $400.
If you're the type that needs to blow money to feel motivated, sure, you can do better, but there's a lot to be said for learning to sound good on a shitty instrument before you are good enough that spending more will actually make you sound better. That's how most pros start out...