Currently, as long as the pins read Disney (c) on the back, they are tradeable. But their terms are always subject to change with little notice.
I have bought from cheappins, DS. And even Ebay has deals, if you luck out and watch closely. I have bought nice traders/keepers for a buck a piece. But that of course is not the norm.
Like your DH, I am ashamed to admit what exactly I spend on pins each trip.

I don't add up the cost. I don't want to know.
The best part is trading! I buy extras while I am in the park to cover me for my non-park months.
Plus as you trade, you meet a lot of great people world wide. Most of us help each other out and we are close community. But newbies are always welcomed!

Be sure to check out the
www.dizpins.com board. And make sure DH gets set up on Pinpics, if he isn't already.
If you have a DS nearby, they probably have in their back room pins for $2 (sale $). Watch for them to come back to the floor in January.