Not knowing all the details, I'd take the offer, do a kick ass job to show them you're value and then ask for more money when it's obvious you're worth it.
I've had a number of "promotions" where I didn't get a raise but took on more responsibility. Then, later on down the road, the money followed. I don't know what business you are in or if you can trust the people you work with but for me this has been a successful strategy.
Last edited by FPS; 10-09-2012 at 16:35..