Harry,
If you are about to launch a niche product onto ebay I would advise the following...
Invest in featured (even gallery) auctions so that it gets highlighted in the relevent search whenever the search is done, not just when it is first listed or about to end (the majority of items that people look at fall into these two categories).
Make your listing stand out, use a template (some on my site or if you want something different then shout up and I will see if I can help), make the listing concise with lots of detail and pictures (hosted away from ebay to save costs).
List in lots of related categories, dont spam unrelated categories as this will do you no good. Even include the keywords
xbox/xbox 360 and ps2/ps3s in the title as this will pull into the four search terms as opposed to just the one.
Utilise the about me page options so as to stream traffic to your own site, even if its a one page information site linked to a paypal :eek: payment screen it will save you fees and develop your site etc.
Remember, invest initially while the market is fresh as you will then be able to establish yourself as a seller of the product and hopefully when (not if) the competition arrives you will be in a volume position and be able to force price the situation to maintain your advantage.
Any questions just shout..
Mike