Go to a tractor supply company.
A lot of old tractors run it in their gearboxes, about 4 or 5 gallons of it.
Thus you get a 5 gallon bucket of it from them fo r little more than a 2oz tube from a mower shop.
The grease is the same .
Yup, tractor supply has 00 grease for $5.29 a quart on their web site and in your local store. Been using it for quite a while now no issues. Link to it is below.