[emcon5]

Here you go, 8 of them for $30. Should last you the rest of your life:

http://www.sportsmansguide.com/net/cb/8-military-style-ponchos-olive-drab.aspx?a=527497

If you want a little more upscale, here are 2 for $20:
http://www.sportsmansguide.com/net/cb/2-new-swiss-military-long-rain-coats-camo.aspx?a=331734