Not changing my opinion until someone shows me an ati card that has at least 600/1000 clock and it's overclockable and under 150$
And lol I got my 8600 to core 720MHz from 540 and 1200mem from 700
A lot of people on this forum know more than you, if I were you, I'd listen to them.
You ask for advice, and when people give it to you, you BS them. Does something seem wrong here? When I ask for help, I listen to the people who respond as they usually know more than me on the subject, I think you should do the same.
Higher clock speeds =/= higher performance. Sorry, that sign is supposed to mean "does not equal", but it didn't come out very well.
Clock speeds have virtually no meaning when it comes to GPU performance. There is much more to it, stream processors, texturing units, memory interface, ROPs etc...
Since you've told us you play at 1680x1050, the HD 4850 is the obvious choice. It has the best performance in it's price segment, it's within your budget and it's overclockable. What's the problem?