To answer your original question - no Wal-Mart will not price match a % off and this is why...
We went to Toys R Us today they had a Lego set "on sale" for $67.95 it was 25% off their regular price of like $89 and change. Went into Wal-Mart today too - they have the same set - regular price.....$69 and change (I was looking at it because DD would like it for Christmas). Wal-Mart has lower prices than TRU almost all of the time.