Don't forget the DE annual report fee ($50) and the DE annual franchise tax ($175 - $180,000, depending on share count). Plus the registered agent ($50) I pay $275/year.
[https://www.delawareinc.com/delaware-franchise-tax/]
The bigger cost for me is the C-Corp tax returns, average cost $806/year, but I suppose that applies to C-Corps everywhere.
[https://www.irs.com/articles/tax-preparation-costs-and-fees]