Someone already mentioned it, but one way to save money is to buy used. I got a set of Ortlieb panniers for about half price on ebay. Craigslist is also an excellent resource. Cooking equipment can be cobbled together easily and cheaply. I use a homemade cat can stove. The O2 rainshield rain gear is cheap and breathable but it looks a little delicate. Instead of buying bike specific clothing, which is always super expensive, I find Target has a good selection of athletic clothes like polypro shirts, shorts and socks that would work just as well. If you're only planning on riding in nice weather, a cheap tent and sleeping bag are fine. Otherwise these are the two items I'd save for.