Budget is good when there is value in it. If the product you are buying for less will serve just as useful, it is more valuable. Personally, I did not want to be stuck somewhere with broken gear, however I did go pretty cheap. I spent under 200 on ALL of my panniers but they are all exactly what I needed. Trek Interchanges in the back and some less expensive bags for the front.
Instead of buying "Cheap" it is better to buy quality used, or handmade/homemade. There are PLENTY of threads on here about making your own panniers. Just search DIY panniers. Good luck and have fun.