Hatsan has the only .30cal break barrel, commercially available. The other guns in it's class are .177 to .25cal., I personally think .22 is best overall at these power levels...
Under $400 "Magnum" offerings are:
Gamo Magnum or Extreme Hunter Pro (Gamo USA exclusive)
Diana 350 magnum (sometimes)
Benjamin Trail XL or Crosman Valiant (less powerful)
Hatsan 135, 125, 150
Maybe some I missed...
To be honest, none of these have had a spotless record. Most of the issues have been resolved or the companies make good on returns/repairs/exchanges. Pick what you like, all is basically a wash in the end. Also, you might find you don't need the extra power and depending on experience with piston guns, might be better off with something less powerful. Good luck getting parts from Gamo. Parts for the Diana are easiest to get (ARH/Vortek), then Crosman with Hatsan nearly trailing. Hatsan hardware (bolts/screws) are very easily damaged. Diana T06 triggers are the best of the guns listed. All will bust a scope eventually, some sooner than later.
I own/owned most I've listed above or variants of, in .177 to .25, and none are what I reach for first. Most are safe queens that might only come out a few times a year.