That's the key word, "value", a lot depends on how you use your camera... if you are a household user who pulls the camera out once in a while for a special occassion or something exciting happens at the house (skunk in the yard, transformer on fire, whatever), takes 10 or 20 shots and puts it away again for another week or more, then rechargeables (excluding possibly Eneloops) are a terrible choice as they'll be dead through self-discharge and lack of recharging on a regular basis when you need them. In that case, lithiums are a much better choice for utility, as they'll last for 100s of pictures, and won't self-discharge in the camera (excluding any draw the camera may pull when "off", which will kill any battery obviously, so pull batteries out of cameras when putting it away for awhile). For the above user, a set of lithiums might last a year or more in the camera before replacement. Having to remember to recharge NiMH each time you need the camera leads to missed opportunities.
Having said that, if you take pictures regularly during the week/month and are good about remembering to recharge them regularly, NiMH are a better value in the long term.
And both are better than alkaline, including the "ultra" alkalines which are all terrible for camera use (but get the job done cheaply at least in a pinch).
So lithiums are wonderful for digital cameras, especially with sporadic periods of usage, but for regular heavy usage (more than 2 days a week and more than a few pictures a session) NiMH will pay for themselves over lithiums in short order. And if you just keep rechargeables on the charger all the time anyhow, then obviously no reason to use lithiums.