The respirators listed at $140 are actually a case of 12x50pc. That's a tota of 600 respirators for $140. (Original price). I'd say that is reasonable.
Now, marked down to 600 respirators for $7.65 -- I'd say that is the best price you'll ever dream of finding!
Anyhow, who needs 600, right? they carry a 1x50pc for $1.28 which is what I got (among other goodies!)