the 3 day pass is generally more expensive than buying tickets for 2 days...and cheaper then buying tickets for 3 days....they do it that way on purpose obviously...marketing...
Dont quote me but I do believe it is 3 to park and 10 per day to enter. There are deals if you plan on going all three days but it is only worth it if you plan on using all three days worth of tickets. I havent heard of any coupons but it wouldnt suprise me.