Price is not a safe indicator of anything. I will go out on a limb and say that you won't get 3ml of pure Oud oil in single digits. If someone is selling it to you in single digits, beware. There are also example of oils that are astronomically priced simply because of the vendor's reputation or popularity. Take ASAQ. They are selling their famed "Thaqeel" Oud oil for $3,733 a tola (10ml). You do the math. And that is for an artificially oxidized oil for which there is no information provided such as the age and species of the tree, the jungle or place of cultivation, the age of the oil, the details of the distillation process, etc.
Perhaps the single most challenging factor for anyone who is new to Oud is the price tag. There is no easy way around it. You must bite the bullet if you want pure Oud oil! It is a precious and sacred substance, not a mere perfume.
The clearest direction I can point you in with absolute confidence is the Oud oils that are being sold at
www.oriscent.com. No need to drop $550 on the LTD oils, unless you really want to (you certainly wouldn't regret it). But, in my opinion, the Ouds listed under "Organic Oud" are the most affordable pure Oud oils available, and they have gone through a meticulous distillation process that is, in my opinion (and to my nose), unmatched by other vendors in its quality and purity.