I think if you have an EZ-Pass you will avoid the 40 cent extra toll. Plus the $6.00 Charleston to Virginia toll is reduced to $4.05.
It's $0.40 maximum for Cash OR a non-WV EZ Pass account. It is $0.26 for a WV EZ Pass account. I have a PA EZ Pass and it charged me $0.40 recently. Info found on the WV EZ Pass page, Toll Rates.