Plantain Shutters from Builder or 3rd Party for new build

I know this topic has been posted in various forms, but I can't seem to find a straight answer.  If you have a thread, feel free to point me in the right direction.

Just purchased a new construction and am looking for Shutters.

Three Quotes from 2 third parties and one from the Builder.  The first, EJ's Home Improvement, is about a third what the other two are charging and is heavily pushing poly (this and the price already make me somewhat suspicious) (should I be?). The builder and the other (Custom Wood Shutters & Blinds) are within $1000 of each other.   

I'm leaning away from EJ, so the real question is do I go with the builder or through Custom Wood?  Does anyone have experience going with the builder vs 3rd party and having any regrets or vice versa?  I don't want to be penny wise and pound foolish.

Long time lurker, first time poster.  Thanks in advance!

Go with 3rd party but also check out more venders.

FYI, at one time (not sure if they still doing it) IP uses Golden West Shutters in their model homes and also offer them as builders option.  GW charges about $22/sf but IP design center charges  close to $30/sf for the same stuff. 

Also checkout these popular one on TI,  PacificWindecor, Bellablinds and OC Shutters.

I went with Orange County Shutters in my homes. Excellent quality and 100% basswood not plastic. I paid $17.50 Sq Ft. .