Automotive brake grease There are a lot of questions related to using automotive grease on bikes. The answers seem to be split between "well, at least you are greasing your bike" and "use the right grease for the job". This answer was really helpful in that it says any grease that is not too thin and not too sticky will do. The problem is I don't know how thin or how sticky the desired grease is (or where my blue automotive brake grease is compared to that).

I was looking around on Amazon and found that small (few ounces) bottles of bike grease are around $10. That seems expensive since I bought this huge (several pounds) tub of automotive brake grease for around the same price.

I have a cheap Craigslist junker. It creaks real bad and everything is covered in a think black paste. If I clean it all off and replace it with blue automotive brake grease, would it really be all that bad for my bike?
A dedicated grease with optimized properties for the application/operation temperature is always best. Automotive brake grease, while not ideal, won't cause any damage to your bicycle. 

Naturally one uses MUCH less grease on a bicycle compared to on a car, therefore the cost of grease is negligible compared to other consumables for private repairs.