It is the same.

You will get a more knowledgeable sales person and probably better service pre and post sale at the local yard. Ask them if they will match the price. You might be surprised.

+1 to both comments. It is the same product, but you'll likely get better service (certainly more informed) from the supply house.

I liken the difference between the supply houses and the big box stores to the analogy of talking to a guy/gal about your car that is from Jiffy Lube vs. a full service mechanic's shop.

First, thanks to all who took time to response to my question. Update: Beside the Anderson 400 french patio door, I 've decided to also purchase a 2 panel/lite unit (fixed), that matches the look and demensions of the 5' wide patio door unit This will provide an total 10' wide, 4 lite, vista view of the back yard. ---Now, the $ stakes have increased-- the saving, including sales tax, is $600+ ! ---As per your sugestion I will consider asking the local lumber yard to match the price; however, that seems like a somewhat nasty thing to do. --A local lumber yard probably can't match the big store-- even if they did, I would only be causing a strain in my relationship with the lumber yard (I need to do business with them in the future). ---So, (1) I am not walking away from $600+, (2) I don't want to bring tension into my lumber yard relationship---- I am thinking I might just, quietly, buy the units from the big store. --Make sense? ---Jaes.

Unless you want the look of separate openings, you should simply purchase a 10" x 6'8" OXXO door. I am guessing on your height since you haven't said anything about that.
It would be easier to install and weather proof.