Ebay is great for getting used equipment, but ebay is also great for getting a 150lb paperweight. I service all types of machines but even I know when it is time to tell the customer that it is not worth the time and effort to revive what they bought on ebay. Sure they picked it up for $800, 1/8th of the cost of it new. But leaks like the Titanic, it can't remember it's settings and most of the parts on it are OEM. When I am done they could have bought a new one with a warranty.
Be very careful when buying on ebay. If they start an auction at $1.00 for a machine that normally lists for thousands you could get burned. I know, I see it everyday when they bring it to me!
i did ok on ebay few times. starting from 1usd is safe for the seller, because ebay has plenty of users and the price will climb up to a correct price. also check the sellers evaluation. that is very important. expect a little bit investment into your purchase and thats it... easy....
Go to your local restaurants and ask them who they use to work on their espresso machines. Chances are that guy will have both new and used machines. You can buy on eBay as well, just make sure you have someone to recondition it.