This is my opinion, if you have the money and want the most up to date CPU then go for it, I don't know how much of a difference there will be in performance between the 2.8 and the 3.0 because I believe they are both running a 533 mhz front side bus and the actual price difference between the two is only around $100.00 USD, so whoever is building the PC for you is basically charging you $150.00 just to drop a different CPU in the socket.
  Intel has a 3.06 processor with 800 mhz front side bus, if by chance that is the CPU that is offered for the extra $250.00 then it would be worth it, because the price difference between the 2.8 and the 3.06 is around $200.00, and the quicker bus speed is where you would pick up performance (along with the faster CPU.)

  Either way, congrats on the new machine!

This setup has 800 fsb  on both 2.8 and 3.0 (not3.06) so I guess it`s worth it `cause it`s still inside my budget.BTW, it`s a MPC,formally Micron PC which I`ve
had good luck for last 2 systems.
                                Thanks for your input guys,
                                                                          Dickby