What's a reasonable price? Unless you find one at a surplus yard, it will need to be made. What material of doors? Those look to be 12" or maybe 15" sidelights. How big is your rough opening?

This will be for new construction, ample room for this idea so no size constraints. Painted door, so solid wood is not necessary. Just not looking to break the bank on this.

Check Habitat for Humanity and architectural salvage in your area...also try craiglsit, ebay, and see if your local dump....yes, many of them have recycle shops for this sort of thing, you do not go through the garbage...

Are you doing a transom lite too? Just thinking that an 8' double door with side lites and a transom would be a pretty massive look. And that a 8' double door with just side lites may look a little off. More of an architect question. Any reputable millwork shop in your town should be able to help. If your not trying to break the bank, don't build a new house. Ha! Its tough to get your appraisal at full construction cost in most parts that I know of.

pair of 2-6 doors, don't think I will use transom. First floor 10' walls.

Very close to:
http://www.eplans.com/house-plans/epl/designers/designer-9887/hwepl10758.html

I would strongly encourage you to go over your idea with an architect. That house you referenced was a nice Greek revival. If you put 8' double doors on there with sidelites it would look wrong Imho. What is your attraction to the doors you are looking for?

Try these: http://www.bing.com/images/search?q=image+double+door+entry&qpvt=image+double+door+entry&FORM=IGRE

I notice the Greek Revival house you featured had just the one door with the one row of lights going all the way around. From the same site here is a very similar Adams Federal, also with a single door, narrow sidelights and a lovely curved transom light. Both are massive houses with a lot of windows and do not have the double doors. http://www.eplans.com/house-plans/epl/hwepl06656.html?from=search

Our house is a broadfront 60s colonial with what I thought was a nice wide entry. It had carved solid double doors with speakeasy peepholes when we bought it, and I wanted so much to add light. No room for sidelights or transom, so we went with doors with glass panels in them. It looks good, and I do think, on our house, that sidelights would not look right.

Do talk to an architect, or check with your building department. One panel (leaf) will open to less than 2'6 clear - very narrow as a functional entry door, and not wide enough for emergency egress.

try craigs list. I saw several today in the greater sf area

http://www.gowestpac.com/exterior-doors/fiberglass-doors

I got a beautiful double entry door for a very reasonable price from ETOdoors.com.

We went with what are supposed to be patio doors with enclosed miniblinds. Looks great, they're primed for paint, but look fine as is, and provide privacy when necessary. Home Depot.