EGR valve differences?

I am looking at EGR valves and there is a standard motor products for $40, an AC Delco for $150, and a Standard Motor for $160. Ok, these are big price differences. What gives?

http://www.smpcorp.com/web_app/catalog/images/EGV318.jpg

SMP for $40


http://www.rockauto.com/ref/ACDelco/214-5393.jpg

AC for $150

http://www.smpcorp.com/web_app/catalog/images/EGV367.jpg

SMP for $160

the $40 one is vacuum only, the other two have electronic position sensors on them (to tell the computer that they are open). The first one pictured will not replace the other two. Someone looked up the part wrong, or the book/computer has a mis-listing. That's the difference in price.

Thank you very much for the clarification