Graphic Design for Mobile App Advert on Facebook

We need some graphics done to advertise our mobile application on Facebook (there is a dedicated system in the Facebook Developers section to advertise applications for iPhone and Android that appear on your wall as an advert). The design of the applications are already done so that of course means its just a matter of resizing and shouldn't take longer than an hour. Our budget is very small, so please don't bid high! The sizes we need are as follows; Icons 16*16 and 75*75, 128*128 screenshots, Banner 150*100, Cover Image 800*150 Two other banners 180*115, 394*150