Here are some older payoffs. Last year the exacta paid $340 with the favorite and a Stewart bomb. Same thing the year before & it paid over $900.
Win, Exacta, Trifecta & Superfecta Payouts 2000-2012
Year $2 Win $2 Exacta $2 Tri $2 Super
2012 $32.60 $306.60 $3,065.60 $96,092.80
2011 $43.80 $329.80 $3,952.40 $48,126.00
2010 $18.00 $152.40 $2,337.40 $202,569.20
2009 $103.20 $2,704.80 $41,500.60 $557,006.40
2008 $6.80 $141.60 $3,445.60 $58,737.80
2007 $11.80 $101.80 $444.00 $29,046.40
2006 $14.20 $587.00 $11,418.40 $84,860.40
2005 $102.60 $9,814.80 $133,134.80 $864,253.50
2004 $10.20 $65.20 $987.60 $41,380.20
2003 $27.60 $97.00 $664.80 $5,591.60
2002 $43.00 $1,300.80 $18,373.20 $183,529.00
2001 $23.00 $1,229.00 $12,238.40 $125,973.80
2000 $6.60 $66.00 $435.00 $3,270.80
Median $23.00 $306.60 $3,445.60 $84,860.40
http://www.anddownthestretchtheycome.com/kentucky-derby/2013/4/29/4284178/kentucky-derby-historical-payouts-wagering