It's the same as anything in life "a budget" is typically that an amount of money set aside for an activity, the reason being to deliver what you want to achieve for the desired "budget". Everything else being equal it apears to me that rider 'a' was placing himself outside of a finance budget and rider 'b' came in either on or under budget.

Money isn't god at all, money is only the deciding factor in making a transaction, your either prepared to pay it or not. In this instance clearly rider 'a' was over budget and so could not be procured.

Apply the above to any business plan or transaction, without emotion and it speaks for itself