My perspective would be yes, cheap steel to work on your form would be fine, have someone watch/record you, look for your cheek weld, follow through, etc as well as watch yourself for the shot through the scope. When you KNOW group can't get any better then look to ammo upgrades. This should be about repeating the good habits and weeding out the bad with lots of repetition and criticism more than drilling a .5" group through the bullseye all day.My current club is 100yrds and there is a state range that goes to 300yrds about an hour away. So 100yrds mainly in the short term depending on how well I shoot. There is 1,000 yard range about 2 hours away but I won't join that unless I really get into this and would definitely upgrade my rifle before that.
So short answer is assume 100-300yrds.
Would throwing steel ammo down range in bulk to work on form be worth it or do I want something better to start? I would imagine even the steel stuff is going to be more consistent then me for a while. 60-70c a round for practice ammo won't kill me I already spend that on my .300blk. I would plan to reload though eventually. I already have a press that I use for pistol cartridges. So would only need to pick up the dies and rifle specific tools.
My brother isn't a terrible shot, but as we're testing loads for his valk one day, his groups are capital GOD awful, after the first 10 rounds I started watching him instead of the target, and his cheek was moving as much as his shots. I pointed out his error as he let me finish testing, and he immediately started kicking himself, muttering about needing to practice more and that was the nicest thing he said to himself.
Catch these types of errors before they become habits and even if your gun hates the ammo, you should still see the groups shrink. When you're no longer seeing improvement, bump up to the top 5 recommended accurate affordable loads (likely cheap hunting ammo), take the best one and practice some more. When you're down around 1.5 moa or better (hopefully a coach will be available for some of this), then premium or handloaded ammo will be able to shine.