I admit to getting into a bit of mess linguistically there by trying to match the sentence structure the original too closely!

Still, I hope the intention was clear. By being in the EU we get benefits. We got those in exchange for giving up some flexibility. When we leave, we regain that flexibility, but we also lose the benefits. The question is, which is greater? So it is reasonable to ask those to be spelt out in a similar way to a business plan that a bank would find appropriate. I don't think I would have much success going to a bank and asking for a business loan but refusing to indicate how I might fund the repayments because it's all in the future...