I bought a 5207 in yellow gold only last week so I am the last to comment about reliability, but I have been wearing it as my daily watch and find it a very plesant dial to live with.
My reasons for buying it were based on the size...39mm, the simplicity of the dial but still a little different and the contrast in hand / dial visuals.
The dial is interesting enough to be different but not cluttered or confusing and the Power reserve hand is always on or about 65 and so by being in roughly the same place all the time it visually becomes invisable to the eye when I look at the time....It is a nice watch when you buy it and it grows even more beautiful after you wear it a while.
As for reliable ADs, I think all 'approved' Breguet dealers are reliable. There is a list on the www.Breguet.ch website.
Pricing is something that is not discussed on this forum but you can check out some web watch sites for a guide.
If you do a search on this Forum Search and type in '5207' you will get a fair amount of info and photos.
good luck,
Regards,
Jack