A studio light kit is a great tool to have but not an essential tool for every reseller. It really depends on what you are selling. If you sell mostly small items that fit inside of a light box then you may not have much of a need for one of these kits.  However if you sell larger items or if you sell something like clothing then this is a great buy for  you.  I use this exact light kit for all of my clothing pictures and they make a huge difference.  This difference is especially noticeable with dark colored clothing.  Before I had a studio light kit my camera would have a hard time focusing on dark colored clothing.  The extra amount of light was enough to allow my camera to focus in correctly on my clothing items.

This specific kit I use by Cowboy Studios comes with 4 adjustable tripods, 4 super bright CFL bulbs and 2 lighting umbrellas.  The tripods are in 2 different sizes and are adjustable.  Also, the angle of the light is adjustable at the neck of the tripod.  Because this is not something that I use every day I love that it comes with a carrying case.  Everything folds up in this case and can easily be stored when not in use.  I am always paranoid that the bulbs may break so I do put them each in their own padded envelope when I put this away just to avoid breakage.

Certainly not an essential for every reseller but in my opinion it is an essential for anyone who sells a good amount of clothing items.  I have been very happy with this kit.