Well, my $1000 system is everything for a 5.1 setup. For under $1000, you can pick up 5 Acoustech speakers (for around $720), then add on a high-quality subwoofer, such as the Cadence X-Sub, and still come in under budget.
Of course, if horn tweeters aren't your thing, there's always my favorite system, which would be a setup of 2pr. BIC DV62si bookshelves, a DV62CLR center, and a sub of your choice. This setup would run $360 for the speakers without the subwoofer. If you wanted some extra output, you coulld do 3 DV62CLRs across the front, and this would run you about $486 without a subwoofer. I don't know if you'd need this though, as the DV62 bookshelves can play LOUD, and they're fairly efficient too.