Ex Pres 

I've sold somethings for well below what I wanted, and have also sold an incomplete Cinelli panto stem for 10X what I thought it would go for. If you're not selling a lot of items where the law of averages helps you absorb the bad sales, then put a starting price where you are comfortable selling to the one and only bidder. But don't have an inflated value in your head when setting that price.

If it's an item that you can get a good handle on what it "should" sell for, then sell it for that. For example, I'll see that an item has been selling for around $55-$65. I'll stick it on auction $42 open, $63 BIN, and it'll generally sell within 1-2 days of listing, often the night I list it.