Crazy simplistic question.
There are as many answers to that question as there are dollars in $500.00.
There are at least a dozen cookers I would personally spend $500 or less on and be real happy.
Need more info; what capabilities do you want?
Set & forget?
Like to tend fire on a regular basis?
What type of fuel do you prefer?
What are you using it for?
Home use? (big family or small family)