My suggestion is don't buy any oud until the last day. Try all the oils. Drip some on cotton balls and put them in small ziplock bags. Label them. Ask their lowest price. Note it down. Also let them burn some chips for you. It might be a rare chance for you, and it is a treat. Smell the cotton balls at the hotel.
Don't skip the "inferior" houses. But skip their spray fragrances. Most of them are very bad.
Don't buy any oud until the last day!