I think the original question has been answered well enough, but I wanted to add to some of the follow-up discussion.
Someone asked why a monopod would be heavier than a tripod. My answer is that the material from which the tripod or monopod is constructed can have a great impact on its weight and expense. Aluminum is a very strong and affordable material. Carbon fiber is stronger, lighter, and much more expensive. Someone who doesn't use a monopod often might not be able to justify the additional expense of a carbon fiber monopod and, instead, settle for the heavier aluminum one.
Regarding the number of exposures recommended for HDR photography. Someone already posted the workaround of using exposure compensation to achieve more exposures on a camera that limits you to three bracketed shots. I wanted to add that some cameras limit the maximum shutter speed that you can set to 30 seconds. So, if you have shots that are supposed to exceed 30 seconds when you're exposure bracketing, those shots may all be 30 seconds unless you do the following. You can set the camera to bulb mode and use a stopwatch (or count to yourself) to manually release the shutter for the longer exposures, or you could use an electronic shutter release cable/wireless trigger that include a timer/intervalometer function. I use a cheap manual cable, set shutter to bulb, and count to myself.