You do not need fancy ramekins. You do not need an oven. Simply pour the whisked egg into a coffee mug or bowl, then sugar, then coffee and mix. Simply nuke in the microwave!
I may be wrong, but doesn't this recipe seem like it would be prepared and served at a super "high class" restaurant yet the recipe may be made in seconds in your own kitchen? Wouldn't you rather keep the wallet? Hello dollar store.