I have been buying and selling lots of different things for many years now (since 1999 I think) and as a bidder, I often pass on auctions with a reserve, so as a seller, I never have a reserve price.
A high-dollar item will have a high price, so as suggested, I start at the absolute lowest price I am comfortable accepting, add the projected fees for that sale price, and start the auction there with no reserve. "If it looks too good to be true, it probably is." and the people with money to spend on what you are selling already know the going rate and if the start price is good but it has a reserve, often it will be passed over. I personally do this all the time, particularly on snare drums. A fair price might be $300 for a particular snare, but the starting price is $275 with a bidder and the reserve is not met- that is a big flag for me- this seller is trying to get more than average for this drum, and I don't even put it on my watch list to see where the price goes.
On the other hand, when I see something rare or interesting (where there may not be any sales history to gage going rate) I might add things to my watch list to educate myself- but there is more to it: If the auction ends with no bids, it may be re-listed, and at a lower price. This can happen with many items that are "on the mark" price wise as well, so if you REALLY want something, you have to be willing to put the time in and keep on these auctions. I scored a big A Zildjian ride this way once...
One other tip is to start mid-week, and run for seven days. This way you start and end at a less congested time (remember to do so when it is convenient for YOU), but still capture the weekend warriors.
One other useful tip: Search for exactly what you propose to sell, and filter the results (on the left of the page) by completed auctions only. This will show these items meeting your description (which can help you to describe it better in some cases) and shows what did and did not sell, and at what prices. I have decided not to sell items due to how low the going rate was at that time- make sure it is worth your while!