Here's an idea.
Why don't you do a month-by-month breakdown.
Use a variety of resources that track all game releases, do try and get a complete list of game releases in each month in a single region (probably US).
Then just break it into 4 categories: first/second party, third party HD multi-plat, third party HD exclusive, and third party total exclusive.
That will actually make your data collection easier. And, unlike your current method, it will (a) allow us to see trends over time instead of a giant, unwieldy list, and (b) allow us to see what percentage of total releases the exclusives represent.
Start with October-December of 2007 to set a comparison point, then jump to October-December 2008.
It seems to me that this will serve your supposed purposes better than your current method. And although it asks you to break down the data a little more, it should actually make data collection easier.
If this is about data collection, and not drawing conclusions, then leave the data out there. Big lists without any other info can easily be manipulated, which is what you're accused of. So put the info back out there. Do monthly lists, with all games, broken down by level of exclusivity.
As an aside, you need to get rid of the "price" stipulation. It is totally contrary to what you claim this thread is about. Two words: Game Party. If nothing else, the huge success of Game Party reconfirms the importance of budget software.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.