I can't remember the price in 2009, heck, I can't remember what I did yesterday.
We change the batteries every six months. But even without collars, the dogs never go near the boundaries of the lot.
Ducks waddle up the hill from the ponds to taunt the dogs, and the dogs ignore the ducks.
Note: We never, ever leave our two dogs outside, unsupervised.

We spent a long, long time on the training process, and to me that is the key to success.
When we finally turned on the current, we had it at the lowest level, and one correction was all it took.
Dogwatch helped a lot with the training.

Just for Thanksgiving though. (US, not Canadian)

The approximate cost was $1100. The antenna (buried in the ground) was about $1 per foot. The collar and receiver were about $250, and the transmitter was about $250. The batteries are replaced every 3 months and cost about $40 (for the year) on Amazon.