OMG! I am probably livng under a rock.....BUT, I just discovered that Dollar Tree has a website:
I was totally floored because I'm not a huge fan of going into the dollar store to browse - It's just not on my list - usually if I'm in a browsing mood I wind up at Michaels. Anyway - I just saw that they have a website and section geared toward weddings....and buying quantities of things like vases or glassware for the tables in quantities and you can have them shipped for free to a local store. So you don't have to worry about there not being enough quantity on the shelf.
HOW COOL IS THAT!
I am pumped and I hope sharing this gets at least one other person excited 
EDIT: I think the reason I don't hit up Dollar Tree more often is that there isn't one in a strip mall I already go to...I have to make a special trip.....and I just don't think of it.
But ordering glassware ---- I'm totally jumping on this train!!!