Just cause it has more strings doesn't mean it's better. Twelve strings are only worthwhile if they're really what you want to play, most players I know play them with slide but if you want to hear some badass 12 string finger pickin' listen to Leo Kottke's "My Feet Are Smiling" record.
As for your guitar, depends on what sound you want, what style of music you play etc. Breedloves are the best acoustic guitars out there, hands down, but they are mucho pricey accordingly. If you can find a good used one within your price range, get it. Those things have soul. Washburns sound great and reasonably priced. Stay away from Oscar Schmidt, poor manufacturing overall. I'm not too familiar with the Yamaha acoustics but their electric guitars are awesome, my boyfriend plays his Ty Tabor sig. series out all the time.
Ebay is a great tool, but if you're serious about playing I'd consider stopping by your local music store (if you have one). While you can get great deals online, there are a lot of lemons out there. Most stores offer a lifetime of restrings and tune-ups if you buy the guitar there, plus some might even offer a discount on adjustments. However if you buy your guitar online and it needs a lot of work done, you'll be spending a lot anyway. Even just putting new pick ups in can get expensive depending on the quality and the wiring.
Congratulations your acceptance! You deserve to be spoiled a little, good luck finding what you want 🙂