It's my experience that anytime I need to buy a BR Deluxe fare that I get the best deal by finding a good consolidator or Asian travel agent.

However, if you are looking for a fare during the summer you may be out of luck. It's high season & discounts are rare.

I very frequently fly IAH-SGN. Off season Deluxe fares are usually about $1150. Summer months are almost always about $1600~$1700.

Good luck!