I use a bidding agent. I decide what the item is worth to me put in a bid and the agent automatically puts the bid in at the last 60 seconds of the auction. Sometimes I win sometimes I don't. I never get caught up in a bidding war and overpay for an item. Another advantage of using an agent,you only pay enough to beat the next highest bid up to your limit.
It always amazes me how many auctions go for way more than retail and then tax and shipping on top of that. One more really nice feature of using an agent is you can set up bid groups to bid on multiply auctions for the same item. If you don't get one, it automatically moves to the next item till you do win one. Once you win the group is closed. Now that is how you get an item cheap,sometimes pennies on the dollar.
If it comes down to something I just have to have regardless of price, I can always go in before the end and adjust my bid limit. Most agents will email you when you have been outbid in time to raise your limit.
One thing you will need to learn when using ebay type auctions,there will always be another. Sometimes it is best to wait. Learn to utilize the search function and set yourself up to get emails on new items of interest.
Now having said all that, I have been waiting for years to run across another Jota. I missed out on a very nice one a while back went for 7500 plus the shipping to Australia. It was a nice low mileage example but not all original as it had some "special" as in 650 parts. It came from an estate sale and the auctioneer called me and offered it up to me at an equal price to the aussie gentleman that lusted after it,just so he could avoid the shipping arrangements. It was only 15 miles from me so it would not have been an big deal to pick it up and ride it home.Seems our brothers from down under are willing to corner the market when it comes to Italian bikes
. I know of one more Jota locally that is all original and under 5k miles. I don't think the current owner will ever willingly part with it. He is however 15 years my senior so maybe one day I will have another shot. 
Some times you just gotta wait 
