Hi,
    So i ordered a few 5870s a month or two ago for 180 bucks, now i cant find one on ebay for cheaper than 240.  At this price increase do you think the 5850s are a better deal or should i just wait and scoure ebay for 5870's the issue is the more time im looking for these cards there is an oppurtunity cost, i figure i could probably order 2-3 5850s today and be mining already  but then i would lose on the hash rate 420 for a 5870 rather than 350 for the 5850.   What do you think i know there are a million threads like this but im just trying to be cost effective right now i dont want to spend more than 4-500 on cards the machine ill be running these cards in is a 4xpci asrock with a sem 145 and 2gb of ram, 1000 watt psu  i think the psu is probably more than enough for 4 cards, either 5830s, 5850s, or 5870 wel maybe no 4 5870s but 3 for sure....

My current 2x 5850 crossfire setup yields about 330 mh/s at 900/1150. The temps are a little out of control so I have it running at 775/1125 right now, yielding 290 mh/s each.

I get about 92% of the hash rate of a 5870 on a 5850.  Plus, I can run 3 5850s on a quality 750-watt power supply, for a total hash rate of over 1Gh/s.  Seems like an easy choice to me.