Beginners need a violin that can be played and doesn't sound so awful you give up in frustration. People who don't know anything about violin think that there's a small difference in sound between a beginner violin and a professional violin and that the sound of a beginner violin is okay for a student. Violinists know that beginner violins have sound ranging from okay to so awful you'll want to quit. Don't bother with the "so awful you'll want to quit" violins, which are sold mostly by internet discounters such as Ebay and Amazon. Not only do they sound terrible, they're poorly made and poorly set up, meaning they're hard to play, hard to keep in tune, and usually need $100-200 worth of repairs and replacement parts in the first year or two. You're better off taking that repair money and putting it toward a better quality violin in the first place. And don't fall for the fake MSRPs most sites post. No one ever sells those cheap violins for the higher price, and they aren't worth it.
There is no one ideal model, and there can be a tremendous variation in sound between two violins of he same brand and model. As for price, marginally acceptable beginner outfits start at around $250, and better quality outfits that will be suitable for a few years cost around $400-600. Professional quality violins start at around $18,000, so anyone who tells you that spending $500 gets you a super high quality violin knows nothing about violins.
You get cheap junk from internet discounters. You get poorly set up violins of questionable quality from guitar stores and general music stores. You get well-made violins that were properly set up with good quality bridge and pegs from string dealers willing to stand behind what they sell.
If you must buy online, try these dealers:
http://www.sharmusic.com/Shop-Shar/Instruments/Violin/Beginning-Violins/
http://www.swstrings.com/catalog/instruments/violin
http://quinnviolins.com/qv_beginnerviolin.shtml
http://www.feinviolins.com
http://www.sullivanviolins.com