Just a heads up guys the arch D size skins can't be done as 'engineering plans' and need to be done as full posters to the tune of $30ish each from local print shops. If they were brought down to ledger size like the others then they wouldn't have this limitation.
That's not always true . . . and the person at that shop may not have been using their head or their shop doesn't print many plans.
The local ARC reprograhics shop (a fairly large chain) ran two sheets of Arch D last week for just under $3/ea (including tax). $6 out the door with a set of custom plans, emailed in and picked up a few hours later. Their print bed would do engineering prints off rolls in the 30" wide neighborhood, so a 24x36" Arch D was no big deal. All depends on which edge they print on the roll.
Just to point out, the local print shop may be perfect for flyers and mailers, and sometimes will fit your bill too, but the spot you're looking for is where the local architects and contractors get their plans printed. In general, look for "reprographics" shops -- what you want to print is their bread-and-butter business.
That being said, dropping down to an ANSI D (22x34) or A1 (23.1x33.1) will get the "bigger than 20x30" size, and will give more margin to fit commercial print shops, since Arch D is at the high end of that rough size. For my local shop, A0, ANSI E or Arch E would have been more spendy . . . I didn't ask by how much, but didn't need to.
Changes the price from 7 bucks to over 30.
