Answered!

Dan Howard had answered my query about Low Tech armor, but I'd skimmed past it in his reply about other things!

At TL1, if you're buying scale armor, you are NOT getting iron scales.

You're getting copper or bronze.

Copper doesn't change the cost or weight, but drops the DR by one.

Bronze doesn't change the weight or DR, but the price is x4 (minimum because it's CF+3 and there are other things that could add into the CF before you're done like fitting).

Thus while a generic set of standard medium scale armor covering the torso is $550, DR 4 and 28 lb. this only applies to iron armor and isn't available until TL 2.

Copper is $550, DR 3 and 28 lb.
Bronze is $2,200, DR 4 and 28 lb.

And they're still -1 DR vs crushing attacks regardless of material.

After TL 2 begins, there's just no reason not to change over to iron armor types unless you want plate.

A medium plate torso isn't available in iron.  They become available in steel at TL 4.  You can get them in bronze or copper from TL 1 though.

At TL4 it'd be $2,500; DR 6 and 20 lb.

Copper is $2,500, DR 5 and 20 lb.
Bronze is $10,000, DR 6 and 20 lb.  By way of comparison, the Basic Set bronze corselet is $1,300; DR 5 and 40 lb.  Clearly if you decide to use Low Tech for armor you'll have to forbid using the Basic Set.

Starting wealth is the killer here.

TL 1 is $500, TL 2 is $750, TL 3 is $1,000 and TL 4 is $2,000.  So a corselet is 125% of starting wealth at TL 4 but 2,000% at TL 1 because you have to buy it in bronze and you have both less money and more expensive armor!

Low Tech offers all kinds of handy modifications for your armor...

If you're willing to take a 1 DR hit you can get a CF -0.6 for Cheap.
Fluting is available for our scale armor for CF +4 and reduces the weight by 10%.  Tailoring can reduce the weight and give -1 to target the chinks.  Expert tailoring gives a -15% in weight for CF +5 and masterful tailoring gives a -30% in weight for CF +29.

So a torso of TL 1 medium bronze scale that's fluted and expertly tailored is $7,150, DR 4 and 21 lb.  Masterful tailoring gets us $20,350, DR 4 and 16.8 lb.  Just 4070% of base starting wealth!  With the 50 pt. filthy rich advantage you start with $50,000...  It's doable as long as you don't have a settled lifestyle.

Strangely I seem to be able to apply that cheap modifier to the tailored modifiers.  It doesn't help much.  Cheap, fluted expertly tailored bronze medium scale comes to $6,820 DR 3 and 21 lb.  Cheap, fluted masterfully tailored bronze medium scale is still $20,020 DR 3 and 16.8 lb.

Doesn't seem to be cost effective to lose that point of DR, does it?

Especially since light scale starts at DR 3...  Iron is $320, 16 lb.  So plain bronze is $1,280, Fluted expertly tailored bronze light scale is $4,160, 12 lb.  Fluted masterfully tailored bronze light scale is $11,840, 9.6 lb.

Heck, fluted expertly tailored copper medium scale is DR 3 $5,500, 21 lb.  Fluted masterfully tailored copper medium scale is DR 3 $18,700, 16.8 lb.

If you're going for fitting, skip the cheap construction.