OP stated pretty clearly that they were on Xbox ....
Very true. Sorry I missed that.
Seriously, tho, if you have a computer that can handle it, maybe take the money you'd spend on the DLC and get Oblivion GOTY for the PC (about $20). That way, you get all kinds of cool mods that enhance your game and almost every one is FREE! Of course, you have to learn to use some tools, but believe me, overcoming the learning curve is so worth it.
If you're stuck with the Xbox, then buy what you can, since I guess these are the only mods you'll ever get.
~ Dani ~