This thread[/url] has some pictures of the module you would have to clone.
Add to this that you need pods, flying leads and clips, and you're better off buying a separate logic analyzer.
actually yes, from the price point of view it was never an issue, we talk about 100-150USD for all parts, pcb, test leads and clips (for single unit, volume - however not really possible here - would be much cheaper). Today (and 2010 it was even higher) the difference in price is about 300USD, so still lot of money to save.
The only reason was lack of interesst (due poor performance of the Logic analyzer in compare to other you could get for 100USD).