There are very few consumer goods for which I place any stock in brands or branding. But bac water is one. For reasons I can only guess at (expensive to build a sterile production line for low-value product?), no other manufacturer seems to produce it, and Pfizer seems to have no interest in expanding its production line; instead, it restricted sales when demand surged.
So here's my take, which doesn't even have the scientific support of bro science: buy one 30mL vial of Pfizer Hospira bacteriostatic water. Let's say if you pay under $20 it's a great deal. Alcohol-swab its top before removing the 1 or 2 mL you need. Pop it in the freezer next to your big bottle of vodka; bac is water and alcohol, just like your vodka. Put the vodka bottle back after you have a shot. Each subsequent time you want to reconstitute a vial of peptides, move the Hospira vial to the refrigerator the night before to thaw. Alcohol-swab the top (wipes, not vodka), DON'T rinse and do repeat. <$2 per recon.
Does each of us really need a 25 case of bacteriostatic water?