Which QBs do you think will be clearly better than Ward and why wouldn't the teams ahead of us either draft them or want a deal better than what it would take to get Ward this year?
Trading up from 9 to 1 costs a lot more than trading up from 18 to 10 or from 23 to 15. That's why it would cost more to get Ward this year, than to try to trade into between 10 and 15 from between 18 to 23 next year.
The Saints scouting department looks at the likely pool of players available in future drafts when mapping out their draft strategy for the current year. If they think there are several QB's next year that are in the same tier as Ward, then they could probably get one of those QB's next year for less than what it would cost to get Ward this year.