I've bought several bits and pieces off of ebay when I was putting together my 503cx and it took a long time to get everything I wanted in a condition that was acceptable - lots of buying and selling. You might be able to get it all for less if you shopped around for each component for the better part of a year but I'd say that's a very fair price as long as it's in a condition that you find acceptable; the 120 CFI is a pricey lens on its own. Will you be able to properly inspect/test the camera at all before purchasing?

My suggestion is: GO FOR IT!