If you are looking for masks or respirators, I have a suggestion 99% of people wouldn't think of.

Look for an automotive paint supply in your city.

Here is an example for one in Houston I buy from. Last I checked the price for 3m n95 mask w/o the exhaust vent is roughly $20. for a box of 20. With the vent are $28. for a box of 10.

[link to www.tascoautocolor.com (secure)]