Don't worry about the price. [He has a job here, after all, something he's sure she'll find hilarious once she's settled and he can actually tell her about it]
And although I haven't experienced it myself -- [and never will] -- those who have returned to their lands only to be brought back here again can confirm that time back home really has been stopped.
I understand not being able to shake that feeling, though. [... except now he's thinking of Guinevere, too, and... sob.] I promise, when you return, Guinevere will be there with you.