Pardus has a button release shotgun listed on their website, and has done for a couple of years. There is no indication of if or when it would be released in Australia. I don't know where else there would be a market for such a thing. Their design seems different than the rest of the lever release or push button designs. The button is on top and at the rear of the receiver. And the button does not just release the bolt, but lifts the round up for the bolt to be able to chamber it:
https://www.youtube.com/watch?v=G4AXTKQ2fnoIn any case, most of the issues these shotguns seem to have are not inherent faults to the push button/lever release design, but inherent to the cheap semi auto shotguns they're based on (except the verney carron, because they aren't cheap at all).
And they seem to think they can charge whatever they want for them, since they've got us by the balls. To me though, a cheap shotgun should be cheap. The buckmaster seems to be the best of the bunch so far, and I 'd like one, but over $2k for what is a cheap turkish shotgun, seems like just too much.
Browning and Winchester and Benelli semi autos can be had for less than that, in other more sensible countries. And the turkish semi autos are as cheap as they should be.