Personally, I worry more about the cost of grinding belts and drill bits and such than I do about the cost of steel.
I was in a discussion the other day about the cost of some steels almost doubling from the price of around 2 bucks up to nearly 4 dollars/lb.
All I could do was shake my head.
These guys having this discussion would take a pound of steel that costs 4 dollars and make and sell knives that cost more than $500.00 and they were complaining about the extra 2 dollars?
Costs me a buck for a cup of coffee.
That said, what you might do is politely ask the spring shop if they have a chemistry spec on the steel they buy. Not just a generic sheet from their supplier, but an actual chemistry from the mill. Every single batch of steel from a mill has a written description of the alloys used in THAT!! batch.
Now, how far down the line they care to keep it WITH the steel depends upon to whom it goes.
Some guys just toss in the circular file. But some keep it.
So, it wouldn't hurt to ask.
It's probably pretty good no matter what.
5160 is not normally an exotic steel.
It's great steel just about however it comes out.
I've got a supply with the following spec:
C MN SI CR MO NI CU V N
0.61 0.87 0.22 0.71 <.014 0.05 0.21 0.03 0.0048
I was able to get enough of one batch that I sent a piece off to have analyzed.
Drops may vary over time.