I just picked up a used R8 for $50. It's missing a power supply and I was told that I would need to use the Roland unit. Is it possible to rig up something else?

From what the sales clerk says the Roland power supply is a bit pricey, and I am taking a risk with the machine as I don't know if it works or not. Before potentially wasting more money, I would like to see if I can at least see if she will power up and make beats.