To answer the question about what I would recommend as a DG rifle and caliber is rather more complex than is easily addressable, other than to say I am building for myself a .505 Burns based on a 602 BRNO action.
I also love the pre-64 Winchester Classic model 70, and the Dakota 76 actions.
The triggers on the Dakotas and Wincheters are superb, as is their safety design. Their actions are silky smooth, and generally need very little work to bring them into top shape.
The square bridged BRNOS more than make up in affordability and strength what they lack in aesthetic refinement. They also tend to be extraordinarily accurate right out of the box. Although their actions are a bit rough, they are servicable as is, and can be tuned nicely.
If they have a single weakness that really needs addressing, it is the strength of their stocks. They tend to break in the heavy Magnums.
A three position Winchester type safety can be added to the Brno 602 and 550 actions, replacing the problematic "reverse polish" safety that they are provided with.
(forward is "safe", to the rear is the "fire" position, opposite of the western standard)
Still, it is an effective safety, and if one is a "one rifle" sort of guy, then training with that type of rifle will inculcate the correct manipulation of the standard safety device.
For those with American designed rifles in their arsenal, I recommend changing out the reverse BRNO safety to the three position type so as to avoid manual of arms mistakes .
How much recoil one can soak up has a lot to do with it, as does magazine capacity and distance to be shot over.
Finally, overall weight of the weapon platform must be considered.
I prefer rounds that have no belt on the cartridge for best feeding reliability, and calibers in excess of .400 for best whackage potential. That means caliber times bullet weight times velocity.
Energy delivered to the target.
The newfangled .505 Burns developped by Dane Burns answers all of these details quite nicely. I wish I had thought of it.
There has also been much recent success with the flat shooting but belted .416 Rem Mag.
The .375 H&H is an ideal plains game rifle, as are the .338 Win Mag and the .358 Norma mag.
A battery consisting of two calibers, one heavy (>.400) and one slightly less heavy (.338-375), should provide adequate versatility for hunting any large game at reasonable hunting distances, on any continent.
I strongly believe that all dangerous game ammo should be hand loaded, so as to reduce the (remote?) possibility of high production manufactured ammo somehow failing at the worst possible moment due to inadequate QA.
As to cost, that is largely determined by the type of action I start with. What sort of stock, sights and fittings the customer requires; and the barrel maker chosen.
Anyone interested in having a custom rifle made is welcome to contact me via private email.
If you want to have some experimental fun with a no frills big bore, go out and get one of the CZ/BRNO 550 rifles in .375 H&H or .416 Rigby. The rifle will cost well under $700.00, ready to shoot. Just be ready to repair/replace the stock when it cracks.