You could always just write the number '10' on ten random tiles and use them as festival tiles.
Since the festival tiles are no longer available from Cundco or Zman (or BGG for that matter), they seem to be commanding a pretty high price. They are going for $40USD on ebay US, which is almost as much as the 10th anniversary edition. You could always get the 10th anniv. edition, take out the festival tiles, and sell 8 individual sets of 'phantom' meeples. I'm sure you could easily make back your money if you were willing to that route.