As you get more experienced on eBay, you might be tempted to use fixed price auctions, just so you can budget better. Its often more reassuring to know that either you will make a small profit on an item instead of having to wait and see whether it makes a big profit or a big loss. However, you should be aware that there are some times when you really shouldnt use Buy it Now.
In the Holiday Season.
The market goes absolutely crazy just before the holidays and thats why you shouldnt list items using Buy it Now. Do you really want to wake up one morning and find that all your stock has been bought up, the current highest bidders on your rivals are bidding double what you just sold them for, and the people who bought your item have relisted it with a starting price higher than what they paid? Of course you dont.
I would recommend that you stop listing anything as fixed price as soon as you get into December, unless you have a lot of accumulated stock that you want to get rid of for low prices.
When an Item is In-demand.
If an item is selling within a few hours each time you list it using Buy it Now, then you really ought to consider using a...