nut flush
I agree with markh and BobbyBlueChip and both gave solid reasonings. Purdue "should" IMO win 6, 7, or 8 games this year. So laying -155 is a lot of juice if you think Purdue wins 8 games and you only break even with them winning 7. Not a whole lot of favorable arguments you can make for Purdiue and their schedule. Good luck with your Purdue bet. 
Let me offer a suggestion on a great futures bet. If you are willing to lay $500 on -155 juice, you should take a look at TENNESSEE! I bet $200 on this wager. 
Over 8 reg season wins -155  
Under 8 reg season wins +125
Here are some facts about their schedule.  
- First 4 games are AT HOME. Sounds easy too me. Nice way to break in your team and get things ironed out before playing on the road. 
- Tennessee only plays 4 road games all year!!!!! Only 1 road game is against a quality opponent and that is against Georgia. 
That said, we just need 9 wins for Tennesse to win our bet!!!  :spotting: 
I chalk up one loss for Tenn. and that is against Georgia. 
I chalk up relatively easy wins against UNLV, Lousiana Tech, Ole Miss, Alabama, South Carolina, Vandy, and Kentucky. Tenn. should win all these games.  
So now we have 7 wins and 1 loss. 
Then Tenn. has Florida, Auburn, ND all at home. You just need Tennessee to win 2 of those 3 and you win $$$$. If Tennesseee wins 1 of those 3, you break even. What are the chances Tenn. goes 0-3 to those 3 teams all at home? I like my chances a lot. At worse, Tenn. should win 8 games this season with their favorable schedule. 
September 5 UNLV   
September 18 Florida   
September 25 Louisiana Tech  
October 2 Auburn  
October 9 at Georgia  
October 16 at Mississippi  
October 23 Alabama  
October 30 at South Carolina  
November 6 Notre Dame  
November 20 at Vanderbilt  
November 27 Kentucky