You can find stuff cheap at Harbor Freight at times. I picked up some 12/16 oz plastic squirt bottles for using polish in from their quart conatianers (e.g. Menz polishes). Also, Sam's Club has 6 pks of spray bottles at times.
i bought 8 bottles from usplastics and they are really nice... the big blaster ones are very ergonomic and nice to use
For 8oz misting bottles, there is a place called the container store near me. If you have one near you, they have a great travel accessory section. I've heard great things about US plastics also. ^