I just found a printable coupon that will get you $2 off a Brita bottle. The coupon is valid until the end of October 2012 so it gives you enough time to shop around and find a good deal on the bottle first.
You also might want to verify with the retail store that they accept home printed coupons because not all of them do.
Print this $2 off couponI stopped using a Brita filter a while ago because I think that the filters are ridiculously expensive and that it didn’t really change the taste of the water. And according to them, the filter needs to be changed quite often which just adds up to the bill, but to me it sounds just like another way to sell more of them. But this is a personal preference, most people I know are big fans of water filters.