330megahas out of a 5850? you're sure you don't mean 5830 i have mine sustaining 320mhash and that was 110 usd from newegg (about 6.5-7 btc at this moment)
Your results are not typical =) No, these are 5850's and 330 mhases is quite respectable. Could certainly go higher with more overclocking as well.