Craft magic item question

[LzardE]

So I have a question about crafting magic items. At level three can a wizard make a handy haversack? And what dc does he need to make to succeed in the check? I'm asking because my dm is saying since it will take two days to craft and I won't have secret chest that its +10 dc to the check because it is twice I won't be able to cast the spell on the item. Is this right? does that mean that a more costly item that take 5 days would be +25 dc if I don't have one spell? If you could tell me one way or the other and post a link in the books I would be grateful.

[Xaratherus]

You only cast the spell once during the creation, not once per day the creation takes; thus it should be a single prerequisite. Thus your DC should be 5 (base) + 9 (CL of item) + 5 (missing prerequisite spell) = 19.

[JTibbs]

Don't forget you can add +5 to the DC and do double the work. So 1 day.

And also don't forget the existence of the spell 'Crafters Fortune' Which gives you +5 to your roll. So essentially halving the time it takes you for free if you already meet the requirements.

[LzardE]

Xaratherus wrote:

You only cast the spell once during the creation, not once per day the creation takes; thus it should be a single prerequisite. Thus your DC should be 5 (base) + 9 (CL of item) + 5 (missing prerequisite spell) = 19.

Can I can a link to where it says this? I want to be able to show my dm