When you find the sign you want, right click (Windows) the thumbnail sign, and choose "Save Target As..."  This will begin the download process (each sign is less than 500KBs).  You will be downloading a .pdf file (Adobe Acrobat file).  You will need Adobe Acrobat Reader to open and print the signs.  If you don't have it installed on your computer, can download if free by clicking the icon:
                  

After downloading the file(s), open them in Adobe Acrobat® and print them.  For best results, we recommend printing these signs on a "photo quality inkjet paper"...it's not outrageously expensive, and the signs will look much better!

After printing out the signs, you can "fill in" your own price by using a black marker to color in portions of the "8"s to create the appropriate number.  To see how to create each number from the "8", click here.