Like Tony said, it depends on your budget and goals. You can spend less than $200 on an okay set of dampers, or you can spend $1500 and not even have the best that's available.
Dampers are second only to tires in importance for your car's handling, so it's not someplace that's good to go cheap if handling is important to you.
I recommend against adjustables for most people. Unless you know very specifically why you need them, you're better off without.
Again, your application is important. A damper designed for a handling car is going to behave different than a damper designed for a drag car.