Are you using an image hosting site ?
If so , you can obtain the 600x800 image url by double clicking that image on ebay . That will high light the image . Then cursor over the image and right click and click 'View Selection Source' . The source page will produce a string like :
<span></span><img index="
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/$(KGrHqQOKocE6vsDvpq+BQ4M5Z6I2g~~60_3.JPG" style="width: 800px; height: 600px;" src="
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/$(KGrHqQOKocE6vsDvpq+BQ4M5Z6I2g~~60_3.JPG" id="i_vv4-39" alt=""></center></div><div id="vv4-39_bdiv" class="ic-p ic-b1" style="height:958px;width:958px;"><div style="display: none;" id="vv4-39_t" class="ic-thr"><span></span></div><div style="display: none;" id="vv4-39_e" class="ic-err"><span>Image not available</span></div></div>
Copy and paste the following part of that string into your hosting up load window :
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/$(KGrHqQOKocE6vsDvpq+BQ4M5Z6I2g~~60_3.JPG
That portion of the string will produce the following image :
I hope that helps .