I'm not wanting to dull your enthusiasm here but the plain fact of the matter is that, if you can't compete with other sellers, then you either need to figure out a way in which you CAN compete, or give it up as a bad job before investing too much and move on to something else.
Some of these ebay sellers are making PENNIES and there's just no way to compete. The only hope you have is if your items are better quality goods, printed to a higher quality or are more original and eye-catching. That means you can set your own price as people can't buy the same for less.