I can buy a mesh bag of 6 for $3 here. I am sure the price is determined by supply and demand. Not as much demand here in Canada yet so they are priced to move? I waited til mine were perfectly ripe, cut them in half to remove the seeds(because I wanted to root them) and put them back together with a piece of wax proper between the halves. I put them in a freezer bag to freeze.
The one I took out of the freezer this week (like a rock), I thawed and made my pudding. It looked just about like fresh with only a little darkness on the surface. I Googled and they said Avacados freeze well.