I have been buying (2) 1500's and (4) 1000's for many years for our, non carpet or pets, main home. At an average price $20 each, $120 plus tax every 3 months is going to get me to look at the DuPont, MERV 11 filters, for a much less cost in a $20-$25 multi (4) pack. FILtrete is a GOOD product, it is just pricing itself out of the MARKET. I will follow up in 4 months on my comparative results. Supply & Demand, free market.