my suggestion is...don't dictate your ammo due to price. decide on what kind of performance you expect, then buy bullets that will accommodate. when you start playing the over .375 caliber game, it costs more to play, period. just part of the deal, big bullets cost more, so, if you find a inexpensive (there really aren't any) 416 400 gr that shoots to the same point of impact as your "go to" 416 bullet, then buy some and get your practice in.
but, DO NOT shoot inferior bullets at game because they were less expensive! you are not shooting at prairie dogs or ground squirrels, so ones projectiles need to be appropriate for the game you are hunting.
remember, all the time, effort, practice and expense of a hunt all hinges of what happens after that bullet leaves the barrel, you can't take it back and it is going to do what it was designed to do. shot placement is most important but closely related is what will the bullet do when it gets there? will it blow up, smear, rivet, change direction, separate? or will it retain its weight, travel in its intended direction and do the job you wanted it to do.
price works for practice, NOT for hunting in my never to be humble opinion. good luck with your quest for the right bullet.