Polk Audio R300 Tower Speakers
Now when buying a little at a time a receiver is required first, then fronts a center next. Here are Polk Audio R300s which you could buy as fronts and rears or you could put bookshelves in the back. These are excellent speakers that are priced at anywhere from around $130usd a pair at the cheapest I could find. If you chose to purchase four as fronts and rears it would be around $260usd (at that price I would recommend it). They are built with a 6.5" mineral-filled polymer woofer and a 3/4" silk/polymer composite tweeter driver.
Polk Audio TSi CS10
As I explained before, if you`re buying pieces the center channel that could match the above speakers would be the Polk Audio TSi CS10 which I found out there anywhere from $79.99usd. This center channel is made up of Two 5 ¼” Bi-Laminate Composite drivers, and a 1" (25mm) Fabric/Polymer Composite Dome Tweeter.
Polk Audio R150 Bookshelves
Now If you choose to put bookshelves in the rear you can use these. Now these the price I found as low as $98usd a pair. These also are built with 1 5.25" mineral-filled polymer woofer and 1 3/4" silk tweeter.Now I have a pair of these in one of my systems as rears and theyre great speakers for rears or a 7th channel on a 5.1 system. I would never use them as fronts, they lack the ability to make a range of bass.
Now as you can see here from the pricing, you could easily purchase all these speakers to create a 5 channel speaker system for around