Pre-built for 500-600? Nope. You can check Newegg's DIY PC Combo's. Some of them are actually decent but most of them have 1 or 2 parts that I'd either toss in a work machine or sell before installing.
And a GTX 730? Man... I'd save up for a better GPU and PSU but that's just my own personal preference. I went with an R9 280X and a Corsair 750W 80+ Gold.