I am looking for a good 1st shotgun for under $1500. Any recommendations? I am thinking either 12 or 20 Gauge, I would go with 20 except ammo is not very common in AUS. 12 Gauge will obviously be a shotgun that I will use for longer but at the moment I am just weighing up possibilities. Any suggestions would be greatly appreciated.

PS
Have been shooting rifles for a few years, up to .300WM