You may wish to look second-hand / reconditioned. The Nokia 6630 is getting very cheap ($40-$50 on ebay, a fistful of dollars more for a reconditioned unit from a network operator) and is still a nice enough phone.
My Nokia 7600 cost me $60, new, two years ago. I don't like it as much as the 6630, but it has reliably done the job for me.