Good grease doesn't make a machine last a long time, good maintnance does though. Why would you spend 10$ or more per tube. Grease quality is based on its viscosity, so the stickier it is the more its worth.
Unless your running a crusher, or something that has high speed bearings then you really don't need it. We don't even use "special" grease for our crusher bearings. 3 or 4$ per tube grease is fine as long as you grease it daily. Keep the pins wet on it, its so pointless to buy really expensive grease if you don't need it.
If I were you I'd search your local market for the best price and go from there, don't even look at anybody who wants more then 10$ a tube.