Agree with MassiveD- if they are to be working drawings make sure they are correctly scaled before you leave the store.

FedEx Kinkos has large format printing and can be scaled up. They charge by the sq. ft. of paper used. (I think it's 75 cents.)

The only problem I see that the paper is not as durable as I'd like to be used as a working drawing (at least not how I use it) which is why I use a full size mechanical drawings on poster stock. Of course I'm old, an not fully in tune with the CAD thing.