K&N filters come with a Million Mile Limited warranty, they can just be cleaned instead of buying a whole new filter. The cleaning kit costs 10 bucks.
BUT the thread title says spend your money, so just do what everyone else does and dump the K&N and buy a Cold Air Inductions intake, they are supposed to be the best.
I like the K&N simply because the sound, 18 HP gains it advertises, and the look. When you really get on it, you can just hear the air sucking in through there.