We do a lot of re-entry tournaments here at the Isle, ranging anywhere from $75 - $2,500.
On thing we've adopted for our fields of 750+ (generally any $570 or below multiday) is to payout based on unique entries.
We go through each Flight's entries, and only count each individual's entries as one entry for each Day/Flight. If John Smith enters Flight A seven times, we count that as one entry for total entries for payout purposes. If John plays Flight B, six times, we'll only count it as one again, so now we've counted John as two entries.
We would have total entries of 1,490 (415 Re-entries), and would payout based on 1,075 total entries. Instead of paying out 150 places, our unique entry scale would pay 110.
We've instituted this unique entry payout for about 4 years now, and have had an overwhelming positive response from the players on it.