Sellers should be aware of eBay's price breaks before listing.  At the time of this writing, it costs $ 2.40 to post an item starting at $ 50 and $1.20 to post the same item starting at $ 49.99 .  The potential of getting an extra penny will cost $ 1.20, and there is no way to get that money back.

At the time of this writing, the price breaks are at:

$  0.99 - 25 cents listing fee.
$  9.99 - 35 cents listing fee.
$ 24.99 - 60 cents listing fee.
$ 49.99 - $1.20 listing fee
$199.99 - $ 2.40 listing fee
$ 499.99 - $ 3.60 listing fee
$ 500  and up:  $ 4.80 listing fee

The current fees can be found here:

http://pages.ebay.com/help/sell/fees.html.

NOTE:  This also applies to MULTIPLE PRICE LISTINGS.  Posting 5 items at Dutch or Fixed Price Multiple Listings starting at $9.99 each will cost the same as posting one item at $49.95, or $ 1.20.  Posting the same items at $10 each will cost the same as one item at $ 50, or $2.40.

ALSO NOTE:  This is only the BASE LISTING FEE.  You can add extras (such as gallery or a picture pack), plus you will be charged a final value fee.  Plus there might be Paypal fees as well.  The initial posting fee might be only a small part of your total fees, but it is prudent to reduce them when practical.

WHEN TO START AT A HIGHER PRICE BRACKET:  A good rule of thumb is that the difference between two opening prices should be at least 5 TIMES the difference in posting cost.  For instance, it costs 10 cents more to post starting above 99 cents, so posting at 50 cents (5 times 10 cents) above 99 cents (the price break), or $ 1.49 would make economic sense.  However, posting at, say $ 1.05 would not make sense.

This depends a lot on your category, your expected sell-through rate, and your profit margin.  However, using the 5 times rule, the following opening bids are optimal:

$   0.01 to $ 0.99 - good
$   1.00 to $ 1.48 - avoid
$   1.49 to $ 9.99 - good
$ 10.00 to $11.24 - avoid
$ 11.25 to $ 24.99 - good
$ 25.00 to $ 27.99 - avoid
$ 28.00 to $ 49.99 - good
$ 50.00 to $ 55.99 - avoid
$ 56.00 to $ 199.99 - good
$ 200.00 to $ 205.99 - avoid
$ 206.00 to $ 499.99 - good
$ 500.00 to $ 505.99 - avoid

Good luck!