A number of years ago, I did something of a focused effort on "best combination of price/performance" for my volume shooting needs.
A big item for me was the total lack of reasonable cost over the counter reloading supplies. As such, I went all in for on-line sources. The hazmat extra hurts for small orders, but becomes much less significant with bulk purchases. I threw in the shipping / hazmat for a typical bulk order (4 jugs) and calculated cost per round of each powder for all my ammo I load in large quantities.
I was fortunate at the time and most all powders were available.
At the fast end of of the burn rate spectrum, the winners were Promo (bulk version of Red Dot) and TiteGroup. I like Promo better for most things, but it does not meter well in small charges and Titegroup will give me a little more top end velocity for some specific rounds. These two cover all my target / plinking type ammo for handguns. If I could not have gotten the Promo, 700x would have been reasonable alternate.
In the low-middle of the burn rate spectrum, I ended up with 2 selections.
Shooters World Heavy Pistol is close to 2400 in performance, is not "finicky" like H110 and does great for things like full power 357 Magnums. I really do not use this in any high volume application, so the 10 lbs (two 5# jugs) I bought should last a while.
I have a couple of special application (357 Max for IHMSA, 300 BO) that really need something slightly slower. I stumbled across some WC 680 (milsurp version of 1680) and included a 8# jug of it in an order I was placing for rifle powder. After burning a good portion of this jug in short order, I kept watch for more. Eventually I scored some more and now have a stash of several jugs.
I do not load for anything that needs a slow rifle powder. Therefore I really wanted to select only one Rifle Powder and buy several 8# jugs of the stuff. In the best "combination of price/performance" category for rifle powders I considered WC 844 (milsurp for H335) and WC-846 (milsurp for BL-C2). The WC 844 got the nod as looked better for 223, and some of my IHMSA needs (30 Herrett, 7 TCU). It will also work for all my rifle stuff that I load very infrequently like 30-30 and 30-06. After using most of my original bulk order, I did a second bulk order and my stash is still over 4 jugs.
As you can see, Milsurp has been a big part of my answer to least cost per round fired. Right now, the easy to use (directly compares to commercial stuff) milsurp stuff that I found is not available. For now, about the only Milsurp you will find is very slow rifle powders from Jeff Bartlett (gibrass.com) and some odd stuff at American Reloading. Some of the odd stuff was actually tempting, but note that stuff comes and goes pretty fast at their web site, americanreloading.com.