I just googled "teacher's supply" for phoenix, and these places have saturday hours...call them...
http://www.teachingstuff.com/page.htm?PG=store_locations
I didn't see flasks on the website, but they sell hotplates, and specimin plates with agar, so they must have flasks and/ or beakers.
Also you can do a starter in anything, a flask just makes it easier...I used growlers until I got my flask.