The 2900Pro is only $159 dollars at Newegg. It performs slightly faster than the 3850 @stock settings and it's extremely easy to get it to 2900XT speeds. It basically is a 2900XT underclocked slightly, in fact you can even flash the 2900XT bios to it. If you look in THG's review of the 3800 series, you'll see the 3870 trading blows with the 2900XT, both come out about equal. The 3850 doesn't compare to either of them in high resolutions.
For all that cheap performance though, you have a few things to lose. First off is power consumption. Unless his PSU is pretty nice, the 2900Pro is not an option. Secondly, it runs decently cool, but that's because it's fan is as loud as a jet engine.
If your friend meets those requirements above, it's the best price/performance card out on the market. I'm sure a lot of people would agree. Where's Cleeve when I need him?