Decide the minimum YOU are willing to part with it for.
Set that as the minimum bid, no reserve. The market will decide how much it is worth. Maybe pick a "pie in the sky" (yet possible) Buy-it-now price.
For example, if I was selling my Macintosh 128K (which I'm NOT, you can't have it even AFTER prying it from my cold dead hands,) I would put it on with a minimum bid of $250 (what I paid for it,) and a Buy-It-Now of $1000.
Ridiculously high starting bids cut down on the early bidders; and reserves cut down on the mid-term bidders. When you cut down on bidders at all, you cut down the maximum price. (For all but the ultra-rarest of items, where it'll go for insane amounts no matter what price you put, like an Apple I.)