FYE is supposedly clearancing out the Socom Confrontation bundles with the official Sony BT headset with them for $24.99-$29.99, though the price is YMMV as usual.
Or....if you don't mind a used headset, you could pick up the Socom PS2 USB headset for $9.99 from Gamestop. If you have some spare earpads lying around, that's all you really need to change out and they work pretty decent for the money.