The magazine is printed with 4-color process colors (CMYK). All advertisements (2-color and 4-color) must be submitted using process colors only (PMS colors should be broken down into 4-color process ...

I'm not very famililar with color printers, but I don't think you can count on very reliable accuracy in the $400 range. Like C64 said, you may want to look at something that handles tabloid size ...