The length of the auction needs to be looked into as well.  Longer auctions have more time to be found, but shorter ones allows for a quicker turn around for items to money.  Long term money versus lower but quicker money is something that needs to be considered.  Personal preference and need will help dictate the needs and routes to go with the time.    

When considering the bid range, attention needs to be paid to fees and charges as well.  EBay charges a listing fee for every item and depending on how you accept payment, other charges and fees can be applied that will lower the actual amount of money that you receive for the sale.  Figuring these into the item price helps prevent loss of funds, and helps keep profits as high as possible.

While considering payment, options of payment need to be addressed as well. If accepting checks or money orders, you need to set a reasonable time period for payment, and decide on a policy if payment is not received in this time period. Online services such as Paypal have options specifically for online auctions and have tools to assist in receiving credit card and online check payments. These companies charge fees, so it is important to include these costs in the price of the item.

You might also consider consulting with an accountant to see what the tax requirements would be for a business like this. This is especially important if you are considering doing this as a long-term business and not just a way to make some quick cash.

EBay is a great source for getting rid of unneeded items, or selling items that you manufacture or buy wholesale. It is not easy money, and some research in business and marketing will help in the long run in providing the most possible profit, while keeping the business running as smoothly as possible.