I think you would be hard pushed to replicate the Beresford even with DIY, you could possibly hack some boards together from ebay and get a working DAC, but the amount of work involved to get the equivilant in a box with a power supply would work out (I am sure) more than the selling price. Doing real DIY would either involve messing about with SMT adaptors to build something, or getting a PCB made which would eat most of the price of the Berisford before any other parts were ordered.
You don't mention where in the world you are, there may be someone near with one they can let you try?