You have the ability to add a deck entry fee to any/all events on the Events screen, in addition to the entry fee.
Select the desired event in the grid (unless you want to add a fee to all events).
Fill in the amount in the Deck Entry $ field on the right.
If you want to apply the fee to all events, click ALL to the right of the fee.
To apply the fee to the current event only, click the yellow ADD/CHANGE Active Event #x button.
The amount(s) will appear in the Deck column in the grid.