Is 1.0 GHz worth it?

Since we currently have 2.2 GHz Pentium 4 processors on the market, do you think it is currently worth it to buy a discounted 1.0 GHz Celeron processor PC for ~$350? Or is 1.0 GHz already obsolete? (If not obsolete, how longer do you estimate itwill be technologically significant — i.e., in terms of meeting minimum software requirements?) Any advice would be deeply appreciated.