How much would you pay to join private course?

I had an interesting discussion this past week with a friend about the merits and disadvantages of joining a private course. My friend is in a fortunate position in that he could join any number of local clubs - his hesitancy is simply that he wants to play a variety of courses and he's afraid paying dues towards just one would compel him to play virtually all of his rounds there. It's a valid point, isn't it?

The advantages are fairly obvious though - far less crowded, great facilities and course, great social opportunity, locker rooms, etc.  

The price options are, surprisingly, more varied than I thought.  Some great private clubs here in the Atlanta area are offering some very enticing dues with quite affordable initiation fees.  I even happened across a great discussion about this very topic (and about Atlanta no less) at one of my favorite golf sites, The Hackers Paradise (discussion found here [1]).   

So I ask - for those who love golf, play as much as possible, but are NOT members of a private course...what is the price point at which you'd consider joining one?

What other factors are involved in such a decision?