$110, 8 ports PCIE, no raid - http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=supermicro+8+port&N=-1&isNodeId=1
$30, 4 ports PCI, no raid - http://www.newegg.com/Product/Product.aspx?Item=N82E16815124020
I have the PCI card, it works fine with Windows server 2012, so I'm fairly positive you wouldn't have any issues with WHS 2011. Don't sweat the compatibility statements. It is slower than other cards, but plenty fast for streaming AV of any sort.
I haven't personally used the supermicro card but have heard good things about it else where on the interwebs.