35 bucks really..yeh ive been looking for a new filter too. i got a room about 2 1/2 ft x 4 ft x 6 ft. i just picked up a 4" fan i think its like 173 cfm. all i need is a speed control and a filter. i had a 9000 for two years now with a booster fan. so would that 4" x 8" work?