From standing around football grounds for hours in the cold for donkeys years I know cheap waterproofs don't cut it. From plenty of time spent in fields and up and down hills again cheap waterproofs don't work. Pretty much everyone will try them, thats why the companies who make them are still going.
A lot of people go on about goretex fabrics and they cost a fair bit but they do work, wear your inexpensive tesco pants and you will end up just as wet as if you hadn't worn them due to sweat, as they are probably single layer they will be stuck to what ever is under them which will also be wet and lack of air layer between then will mean you will be cold so cold and wet there is no point bothering with them in the first place. Ohh yeah probably better without them as the sweat will smell where the rain wouldn't.
I now have 3 coats that are worn depending on conditions in combinations if needed, lightweight fleece great for cool days, lightweight waterproofshell great for wind or rain They are worn together if cold and wet and a down filled parker, really cold down is awesome -21 in new york I was sweating sat on the open top bus tour upstairs. for my legs I can just wear a thermal baselayer under jeans but I also have a pair of snowboarding pants they are great and really warm.
EDIT:
I'm no sports photographer