a 3 oz tube of park or phil or pedros grease can't be that much and will probably be the last bit of grease you'll ever buy. A 1lb jar o white lithium grease from a hardware store will cost the same and you'll have 4 times as much, lasting you 4 lifetimes.
I don't mind paying the same amount for less qty- i'm not a glutton, and I'm only buying it 1-2x a year.

Shopping around for a 3oz tube of grease seems like a lot of effort to save a couple bucks. Is there a bike geek friend that has some you can borrow? and maybe his/her guidance?