A 10 day, Park hopping, no pluses, no expire would be $353.58 advance price.
$340 if you get it through Maple Leaf which Deb Wills has on her site.
A premium...10 day, Park hopping, pluses and no expire would be $401.51 advance price and $384 through Maple Leaf. If you buy at the gate, you will pay about $10 more.
The point of buying more days than you will use this trip is that the more days you buy, the less your daily cost is going to be. Disney is rewarding those who make longer trips. If you buy a 10 day PH, no Expire pass, you will pay about $35 a day versus the almost $60 for a one day pass.
Another example is my AP...I have 30 days on it for last year...about $16 a day!!! No pluses but we don't use them, so no big deal.