I need to turn $300 into speakers

I'll say it again: go shopping.  Go out and listen and buy whatever you can afford that sounds good to you.   That's all that matters.

Oh, and the recomendation that you "keep the system all the same" is 100% a matter of personal preference.  There is no real reason to do this other than if you want to, or if you are being paid to!

Yes, in general this forum frowns on non-authorized dealers. 

But more than that, this forum tends to want people to understand what they get when they purchase from non-authorized dealers.  In general this means loss of factory warranty, possible B-stock or refurbished products or even fakes (which is one way non-authorized dealers "got all that inventory") and the hassle of dealing with internet sellers and having to mail gear back and forth in case something does go wrong.  The best way to get support and service for any product is to purchase from authorized retailers, and the best authorized retailers are the ones with businesses in your town.  Plus, I always recomend you never, ever purchase audio equipment based on brand name, friend's (or internet) recomendations, looks, or price alone.  What matter is how it sounds TO YOU and unless you have actually listened to something you do not KNOW how it sounds to you.  There is nothing worse than spending money, installing a piece of gear, firing it up the first time with that feeling of expectation, and being disapointed by what you hear.  Shopping for price alone is a fools game.  Plus, be sure to include the cost of shipping and handling and possible taxes VS only local taxes in any Internet/local price comparison.