I'm told cost-wise they're not too bad to load for, but they're fiddly - something to do with the way the bullet it seated or lubricated or something. You're right that they're easy to obtain though - pretty much every gun shop I've ever been in in Australia has at least one. I usually advise new shooters to avoid them because you can't get factory ammo for them. There's one or two people making bespoke loaded ammo but it's not especially cheap.
I'm told they're good for shooting foxes and rabbits - more oomph than a .22 and longer range than a shotgun. Interestingly, I've heard quite a few have been rechambered for .357 Magnum over the years. I've never seen one but it would definitely be a fun plinking/target/small game rifle!
The price of ammunition in this country continues to surprise me, given there's a surprising number of shooters and not a huge variety of commonly encountered calibres. Even the stuff that's made here (.22, .223 and 7.62x51) costs a lot for some reason.