No. only 4xxx and up support OpenCL. And I think my WalMart still had a GeForce 6200 (for around $70!?!) last time I looked...*shudder* 5770/6770 seem to be good deals regarding $/MH right now, mine cost me $85 and gets 221 MH/s.

EDIT: A 5830 is a better deal if you can find a cheap one. There are a few on ebay, like this one:

http://www.ebay.com/itm/SAPPHIRE-ATI-RADEON-HD-5830-Xtreme-1GB-GDDR5-PCI-Express-EyeFinity-BF3-MW3-/200658002949?pt=PCC_Video_TV_Cards&hash=item2eb8262405#ht_4839wt_1185