dont buy no speakers, buy an amp and the subs cost is slightly different but the sound makes big difference, for a while i only had my stock front speakers connected and the subs, and still didnt listen full volume, (on ebay you can get an amp and subs for around 200$) i recommend subs and amp same brand
this is quite possibly the dumbest shit I have ever heard. Please stop contributing.
Also there is a complete audio forum on here if I remember correctly, and there are plenty of people there who can help point you in the right direction with how much you want to spend vs the quality and sound you can get.