To get a decent home theater system expect to spend somewhere in the neighborhood of $399 or higher for the receiver, $499 and higher for the speakers/sub, $150 or higher for the DVD player, and about $200 or higher for your connections. (Speaker wire with maximum run of 25 feet would be a 16 guage wire, so you would need a 100 ft roll for $60. Opt. cable 1m - $40. IL300MKII-2m - $40. MB300SW-12ft - $40. MVSV32M - $40., those would be your most basic options and that is assuming you dont have other components other than receiver, dvd, and tv)
You can look for package prices out there, such as the Good Guys has their AVR1801 and Take 5 package for $999.99. The speakers by themselves normally go for $499.99 + $299.99 for the sub, and that receiver goes for $499.99 so you are saving $300. That doesnt include a DVD player or you connection wires, so tack on another $400 at the minimum.
When you find a package price, make sure its not a "home theater in a box" as these use lower quality pieces all around. There will be paper cone speakers (worst quality), and usually chip amplified/peak rated receivers.
Additionally, with most of the better quality machines, you can only buy them from Authorized dealers. That for the most part precludes most online vendors. If you dont buy from an authorized dealer, there is NO FACTORY WARRANTY what so ever. You can even check on manufacturers web sites. See Denon or Klipsch's sites for examples, but most manufacturers have it on their sites. The reason for this is simple, authorized retailers pay certain royalties and go through certain training to obtain the authorization. If the receiver has been resold by an unauthorized site, they have no idea what has happened to that receiver. It could be refurbished, or overstock buy back. Thus, either the company feels that there could be either unfair competition or too many problems with the pieces and consequently gives you no warranty.
So its truly buyer beware with online deals, as you may not be getting what you think you are getting. I have seen this time and time again.
If you have any questions, feel free to ask away.