With all of the plugging for Unique, I will throw in a different viewpoint. Even though I have been using Unique for 35 years, I really see it having value more in its flexibility than in actual performance. When I have evaluated it side by side with other powders, it never seems to perform any better than something else.
For all my high volume "economy" loads I have moved to either Promo or Titegroup. Promo is a bulk version of Red Dot available only in 8lb jugs.
My 45 colt (TC Contender) allows use of really stout loads but I gave up pushing that gun a long time ago. Unique would allow for a little hotter "mid range" load than Promo, but the difference is too small to matter for me. The 2000 Alliant Booklet for a 250 gr lead bullet gave 6.0 gr of Red Dot for 830 fps and 8.0 gr of Unique for 850 fps.
Promo is very flexible in its own right. For loads in the 38 SP, 45 Colt, 45 ACP and my various magnum handguns (32, 35 & 44), Promo is nice and bulky and gives me plenty of bang for target loads. It is also famous for widespread rifle use as "The Load" made popular by Ed Harris (13 gr of Red Dot).
I have a big jug of Unique and keep trying it when I get a new gun. As previously stated, I have yet to find a real winner with Unique.
Having mentioned Titegroup, I understand why many choose not to use it. I reserve this for a few select applications where it works better for me than Promo. Mostly I use it for either small case rounds (32 ACP, 9mm) and/or loads where the equivalent charges of Promo are too small to meter well in my RCBS powder measure.
When you combine cost per pound of the powder and required charge per load, Promo and Titegroup are probably in the top 5 for economy. Of the two I consider Promo much more of a general purpose handgun powder. Of all the more economical powders, it has probably more published load data (use Red Dot listings) than any other.
Part of the reason for my post is the knowledge that running out an buying any specific powder will be hit or miss right now. Knowing that Promo / Red Dot are reasonable options can be a good thing if you run across some for sale. Promo was in stock last week (out of stock now) at Powder Valley and was priced at only $132 for the 8 lb jug ($16.50 per pound plus shipping and Hazmat).