We've got 'em, but the shopping cart button isn't on the website yet, and the mail-order with a US Postal Service Money Order price is what's listed on the webpage - http://www.ronpaulstickers.com/vertical_sign.html
We debated the 4.5x24 vs. 9x12 sizes - both printed four to an 18x24 sheet (one sided). Experience over several years has shown that the vertical sign is well received. Since we only get the best prices on printing when we do huge quantities and we don't have a whole lot of storage space available at the print shop, we opted for the vertical signs at this time.
Believe me, I would like to offer the 9x12 one sided coroplast signs, but I have to work through some obstacles first.
FWIW, at the rate we do the two-sided 18x24 signs, doing a smaller run of one sided 18x24 signs would not result in any substantial savings over a two-sided 18x24.
Our 24x36 coroplast signs are one sided, but are really too wide for poles without something to re-enforce it against strong winds.