I checked the plugs and no sign of oil on them, doesn't this mean the problem can not be the valve cover gasket, I got that impression from others on the forum.
No. Oil on the plugs might be due to a leaking head gasket, but not the valve cover gasket. No oil on the plugs is good
As Peter has described, changing the valve cover gasket is a cheap DIY job, or an inexpensive job for a tech. The head gasket, worn valve guides, worn piston rings would all create high oil consumption and create a large bill for you. It sounds like yours is the simple, cheap fix!