The kill zone on a deer is actually a rather large target at over 8" so again I disagree cheap ammo can serve a purpose if it allows you to get off the bench and actually practice enough shooting in field positions. Surplus and steel cased is more than accurate enough for field shooting practice.
Something that in my opinion requires at least 60 rounds fired before season. So you'll spend well over $50 just to practice for the season with a 270win......Unless you're one of those hunters who pride themselves on shooting the same box of "shells" for 20yrs.
Shooting a lot of inaccurate ammo doesn't make one proficient.
It goes a lot father than not shooting ANY expensive ammo. That practice you got on trigger and muzzle control with the cheap stuff doesn't go away when just before season you "sight in" your gun for your favorite hunting load
The slob hunter merely insures his rifle is still "sighted in" a real hunter takes the time and expense to make sure HE'S still sighted in as well. One only takes 3 or for shots, the other......well
Also don't make the mistaken assumption that cheap ammo always = inaccurate
123 grain Monarch FMJ steel cased 7.62x39mm purchased at under $4 a box