I'm against paying for DLC altogether. I know it's the way of the future and all but that seems like a cop-out. It relies too much on external forces. If I buy something I want to actually buy it, own it, be able to hold it in my hands. If I buy something ethereal I feel like I'm getting ripped off. Which is why I have so many CDs.
Plus there is the issue of corruption, and buy that I mean, your hard drive gets corrupted for whatever reason and you have to reinstall. Assuming you only backed up your data files, (if you backed up anything at all) you just lost the only copies of all your DLCs. I guess you can re-download it, but what if there is a server failure, or your Internet is down, or worse yet the company lost everything and the server no longer exists. Am I the only one who owns really old games? Do you really think Valve will still exist in 20 or 30 years? (I say Valve but that could apply to any company.) True it's unlikely you'll care at that point, but still. Plus, even if Valve exists, Steam might have shut down due to lack of interest. You remember Microsoft's Plays for Sure DRM? It required you to call a server to play your music. Guess what happened to the server.
I should really write a full blog post about this.