I'd say as far as versatility goes, the Barney's Freighter Frame and the Hunter or Pinnacle bag would be the way to go. Solid platform that will haul more than you are able, and easily converts from just a pack frame for hauling quarters or odd packages, to a versatile bag that you can fit a ton of gear in. I have only used mine very little, but I guarantee that you won't find many negative comments on them. Still outside of your price range, but I'd suggest saving a bit and buying once, than twice when you need to replace a lesser model regardless of external or internal design. Kifaru are no slouch as far as packs go either.
For the stated money, look into a Kelty Cache Hauler, or a Cabela's Alaskan Guide. If you care for them properly they will do what you want, including the budget part. You might give up a bit of comfort or build-quality, but these will work.
"If you wanna play, you gotta pay" I would recommend one of the packs from Barney's Sports Chalet. I have used one or the other iteration of these packs since the mid 80's. When my sons started hunting I purchased the same for them - couldn't see why the sons shouldn't have just as good equipment (or better) than Dad. At least that's my rational. Some of the highest quality time I have spent with my sons has been time shared in the field. Good Luck.
I have a cabelas guide frame pack and bag. I don't use the bag much any more, but I still use the frame to haul meat and sometimes firewood. It has seen quite a bit of heavy loads and still works fine. For the price range that you are looking at it will serve you great for many years.
Lol, Sometimes you just have to make do with what ya have (until you can save up and get what you want). Im pretty sure people were still killing and dragging back meat to camp lonnngggg before these 1/2 a grand bags were around.
If I only had the funds for either a fly-in hunt or 600 dollar pack, it would be a no-brainer..
Whatever you choose, getting a feel for your gear on even average hikes (dry runs) can make a huge difference when it comes down to the long-haul.