One thing I thought about that if the Mirror loses, they can appeal the decision. Granted, as with the DM's parent co. and Meghan's suit, the Mirror may choose not to, but there is the option. In that respect, the other media groups could appeal if they lose their cases. In theory, Harry could potentially be tied up with each case for quite a while and spend even more money.
It was something to consider...there's still this present case and the other media cases to get through first. Well, and Harry's other case considering his security, if the Govt. loses, they could appeal also.