$123,456 · WTB: Cheap / Inexpensive / Used Machine to Mic 5.1 Audio

Exactly what the title says. I need a computer -- it doesn't matter if it's a desktop, laptop or "mini" PC -- that I can use to mix 5.1 audio in a program like Wavelab. I don't necessarily need speakers, but would consider options that include them. The machine only requires an internal or external soundcard or break-out box that supports discrete 5.1. I don't need a machine that is geared toward gaming or video editing, that would be overkill for what I want. I'm just looking for a relatively inexpensive option for mixing some community audio in 5.1. Please send me offers with computer and audio details and your asking price. I may be able to do a trade for a musical instrument, such as a synthesizer, depending on what you're offering. Thank you.