I would say a lot, but it is a relative term, some would say it is huge.
Here is a fairly recent pic (more added since it was taken).
Last I figured it was around 28 gallons of oil, 24 oil filters, 4 gallons of ATF, 12 bottles of fuel fuel cleaner and a gallon or two of coolant.
This is a few years worth of oil for my truck, car, and bike; as well as some fairly regular changes on 3 family members vehicles.
Spent well under $200 for all of it. Probably $1000 retail price for it all.
Am I a hoarder, sure, why not. There are worse things to collect.
I am sure that there are plenty of things that we all have that others could say are a waste as well.