Don't know if anyone already posted this, but I was strolling through Target this evening and stumbled across some great school supply sales:
Elmer's 2-pack disappearing purple glue sticks (the small ones) 20 cents, no limit
Papermate 10-pack pens, blue or red 50 cents, no limit
One subject spiral notebooks (college or wide ruled), 5 pack 50 cents, no limit
Duracell AA batteries, 2 pack $1, no limit
Vinyl 3-hole binder pencil pocket 50 cents
Someone asked about Expo dry erase markers, and I believe they were two 4-packs for $3. They had a ton of other stuff, some very cheap.
Elmer's 2-pack disappearing purple glue sticks (the small ones) 20 cents, no limit
Papermate 10-pack pens, blue or red 50 cents, no limit
One subject spiral notebooks (college or wide ruled), 5 pack 50 cents, no limit
Duracell AA batteries, 2 pack $1, no limit
Vinyl 3-hole binder pencil pocket 50 cents
Someone asked about Expo dry erase markers, and I believe they were two 4-packs for $3. They had a ton of other stuff, some very cheap.

If I can help defer that cost at all with my bargain shopping I figure it will benefit both the teacher and my own child as well.
I'm sorry you had that experience. I don't think you are asking too much when you had to make two trips to get what you wanted. Most Walgreens I've visited don't enforce that limit printed on the coupon. I definately think a call/e-mail/letter to Walgreens corporate office is in order. I've heard they have been very good about handling that sort of thing.
I hope he realizes that there is no reason a customer should ever be treated that way!!!