Substituting Springform Pans for Size?

I'd like to try this recipe from Saveur for Hazelnut Sbrisolona. It calls for three 6" Springform pans but I really don't feel like shelling out $35 - $45 for three 6" pans I may only use once.

The total area of three 6" Springforms is roughly the same as one 9" Springform, other than aesthetics do you foresee any problems doing this?