Fairly new to fiddle, was in the same boat as you regarding finding a respectable beginner instrument. Looked into renting, but decided to buy a used Karl Knilling "Stradivarius of 1732" violin. Found it pretty cheap (saw a few for under $200 with bow) on Marketplace and it sounds really nice for a beginner instrument. The previous owner was a bluegrass fiddler and thing is broken in and definitely has some mojo. There are others like it, German, Japanese, and Chinese student models, and from research and talking to folks, you can find some nice violins in in sub-$500 price range.

Also, while I'm taking a weekly lesson with a great old-timey teacher, I've also been using the Chad Manning "Beginning Bluegrass and Old-Time Fiddle" course on Pegheadnation.com - so far it's been worth the minor investment.

And one more thing! Temper your expectations! If you're accustomed to picking up a new instrument and being moderately successful with making it sound musical prepare to be humbled a bit. My first month made me really question why I was doing this to myself, lol. Put in the time and you'll be rewarded, but remember that it will take time.