Crafting a belt of mighty constitution +2 requires 4 things. The spell, the feat, a CL of at least 8, and 2000gp.
A 3 rd level wizard with starting int. of 20 will have a spellcraft check mod. of +11. The craft DC for a CL 8 item is 5+8 = 13. Add the fact that the CL requirement is not met, and the DC is now 18. The wizard only needs a 7 on a d20 to correctly craft this item. Is that accurate?
What would be the CL of the crafted item, for determining its saving throws? CL 8 or CL 3?
Given the money, crafting a +6 belt would be as easy for this wizard. The fixed DC mod of +5 doesn’t factor in the difference between the actual caster level and the CL requirement, nor the does the CL requirement, for higher enhancement bonus, scale. Is that intended?
If I correctly understand that the header CL is actually a requirement, it should be added to the requirement section of each items, or clearly stated in the creation rules that it is a requirement. An enhancement bonus on a weapon, for example, clearly states the minimum CL being 3 times the bonus to be added.