That isn't bad. Personally, I might stick with a bunch of
Dayton MK442s for the speakers, at least the front stage. They are $50 each, so that is a good 3 speaker set for $150. You could also just use a set of
these,
these, or
these as surround speakers, and save a bit more money and have a speaker that is easier to mount.
That AVR is a bit behind the times, I would grab something from accessories4less around the $300 mark.
For the subwoofer, I would grab a couple of
these or
these. For a single better sub, I would look at
this (when it's on sale) or
this.
Remember that cables, mounts, and all the other accessories do add up and will not cost an insignificant amount on a tight budget. Do not buy audio or video accessories from an electronics store like bestbuy, the markups are insane. Monoprice and bluejeans cables are a great alternative with sensible prices. If you need a wall-mount for the surround speakers, get
these.