Clothes in general are easy to find and do not need to be expensive. You can generally find good base and insulating layers, along with gloves, hats and socks in your local thrift or surplus store for next to nothing.

The three items that I would spend money on are: pack, tent and boots; although the latter can be an old pair of running/trail shoes (depending on your location/time of year). I do admit, that I am not knowledgeable enough to know what the best combination for under $200 is, for your specific area-- but I am sure more experienced members will be along shortly to give you better information.

Other good places are Craigslist and Ebay for used/affordable gear.