Ikido, your once fired brass is worth a few cents each. To deprime it, you must buy a set of appropriate tools - typically a press, and dies at a minimum. To tumble it, you would need a tumbler, and medium. These all cost $$, and will not increase the sale value of your brass anywhere near what it would cost for the tools.
Redding, RCBS, Hornady, Lee, and I am sure a few others all have good web sites which explain the whole reloading process, including case preparation, and detail the kit you need. They also have on-line catalogues with prices, so you can estimate the set-up cost, as well as compare them to the price of new, unfired brass offered by several on-line vendors.
A couple hundred cases probably are not worth selling, but would create significant good will were you to give it to a fellow shooter at the range one day. Or, it also makes a good start on a brass supply for a new reloader. Reloading will result in a per shot saving of about 50 to 60 %, if you do not count the cost of the equipment. Since the gear will last a lifetime, (I'm using some dies that are at least 40 years old) that is probably fair. What reloading will do is provide you with a better understanding of your rifle, your bullets, your shooting, and will probalby allow you to shoot many more rounds per year, for not too much more money.
It can be confusing, intriguing, risky and rewarding. If you are patient, capable of learning relatively intricate cause and effect concepts, and careful by nature, go for it. If you have the attention span of a gnat, want instant answers and feel there is one simple solution to any problem, or like multi-tasking while indulging in the use of mind altering substances, then I don't recommend reloading as a pastime. It helps enormously not to have an ego the size of Ontario, and to have healthy love for your eyes and fingers. Much of what you will see advocated here on CGN reflect both a huge ego and a complete disregard for physical well-being.
if you meet the proper criteria above, I heartily recommend getting into reloading.