In a way, you suppose this is true. Sunsets are free. Love is free. A warm hand in yours is free.
The sunset, though, in all its two-red-giant glory, comes at the price of eighty five billion soldiers, keeping the beautiful planet beautiful by stopping the Daleks from taking it over. The soft, fertile ground beneath your plimsoles is planted with the bodies of the people that once lived there. There's a price.
A warm hand in yours, yes, that's free. But the contact comes with a sense of fear, of impending doom, as monsters chase you through the hallways of some random corridor, some frightening alleyway. You know you're too repressed for contact otherwise, it takes a bit of emotional payment to get you to open up.
Love is free. No, no, it's never free. She loves you, you're not stupid. She looks up at you like you're some sort of Jesus in miniature, and the flirtations across the console are far from subtle. You can't help that you don't love her back. It's not her, it's you, and that sounds pathetic, because it is. She has love which, in a way, is free, but she's stuck having to settle for the discounted brand: unrequited.
You look up from the engraving on the wall. The Best Things In Life Are Free. Carved onto a World War II memorial. Textbook Irony. That War was far from free, and you were only moderately involved in it.
Martha's still standing there. She's got a gentle sort of confusion on her face. She's not Rose (the love that cost you), she can't figure that it means you need to think. She hasn't quite learned the concept of "the Doctor's space."
You have to reply, though. She's waiting. "Hmmm?" Well, it's the best reply you can think of right away.
"Are you all right? You got all quiet there for a minute."
"I'm all right," you reply, "I'm always all right."
Muse: The Doctor (Ten)
Fandom: Doctor Who
Word Count: 339