Buy a new bottle of distilled water, pour some into a glass measuring cup and boil it for a few minutes. Inject the hot water into a sterile vial and then use a slin pin to measure out .25 ml of BA for every 10 ml of water, and inject into vial. Wait for it to cool before using it to mix HCG. Store in fridge. Cheapest bac-H2O there is. And no, the 2.5% concentration of BA doesn't sting.
Use your google. I get mine mail order. the only problem is that I can get only 90ml at a time. I can't get any less. And considering I only use 2cc for every 5000iu's I have a lot left over. luckily it has a long shelf life unlike the hcg.