Do you want a full size real rifle, or a tactical bullpup...
I like the looks of the impact and maverick so to speak but in all honesty it’s more about being reliable and accurate at the end of the day.
A new Impact seems out of your price range, and is a aftermarket accessory/tuner giant,, for sure. Won't go so far to say its high maintenance, as many of the stories we read here are self inflicted from good intention tuning/mods. Might find a good shooting used one in our classified that almost fits in your budget
I have an older impact and it is a great rifle with so many tuning parameters/accessories its mind boggling. But the impact would be good for you if you want to tune for slugs at the longer ranges you've spoke of. Other than that, a Crown is my next rifle. Some say its a impact in classy clothing....

So many threads on the new, not yet proven durability, with not much real world Maverick long term experience, you can figure if that fits your needs/desires for yourself...
Or you could get the often recommend bulpup Taipan thats a great gun that seems to be more low maintenance/robust than the tuner guns. Although it is quite tune-able with a stock great trigger that adds to its accuracy imo. Used guns like the Russian EDguns and Brit Daystate, are also a high quality powerful accurate option that preowned/used might fit in your budget. The new Krals are also a great mid level gun...AGT Uragan,Vulcan, are also a high quality powerful accurate option
You also could get a Crosman Akela to try out the bullpup platform and see if you like it at 1/3-1/4 the cost. If you bought direct from Crosman with our 25% discount and free shipping Fri, probably could try it for a short while and if its not perfect for you, return it, or sell it here. Then you'd know if bullpups are your preferred platform.
In reality, a good example of any of the above mention guns, will serve you well and probably won't disappoint coming from a mRod...
jmo