I've used an old craftsman with the $15.00 cartridge filter for about 20 years. I have to blow out the filter with compressed air whenever I empty the tank. The darn thing still works well but the universal motor is very loud.
After helping my brother finish his basement and using his shop vac brand
bought at Lowes I bought one for myself. The filters are just as pricy but the motor is much more quiet than the sears