|Why to you think you will get more speed with a newer motherboard if you use the same processor and RAM? The differences between compatible models is not that great. |
Adding RAM and taking care on HOW you setup Photoshop will probably help more than a new board.
Are you using the 32 bit or 64 bit version of Windows 7?
Your board can use 8GB of RAM. If you are running Windows 7 64 bit you can take advantage of more than 4GB of RAM.
What graphics card are you running?
I think that most of the time a refurbished board is just a board that was returned and tested as good. Many times folks will return a good board because they don't know what they are doing. As jefro said, the price and warranty need to make sense.
I don't think there is enough savings in most cases.