well, the ebay ones are fricken expensive. I just listed mine with a reserve of 120 with shipping of 110. I'm practically at the reserve now, although i'll let it go for less if need be. the way i see it, i paid $150 for 8 kegs, this machine, and the hosing/connectors it came with. even without the machine, thats $18 per keg. i couldn't care less about the machine. to me it was spare parts. I'm assuming you got a good deal on it yourself, so you should definitely be able to sell it for what you paid or a little more.
when customers see ours for a couple hundred and the other listings are for over $500, they'll buy ours!
EDIT: also, my listing fee was like 2.40. i didn't go all out on the features because the people buying these know what they want. You don't have to wait for mine to be gone, go ahead and make yourself some money! now to find a box to ship this in....perhaps build a crate?