Presumably you are paying your designer to develop plans for your pergola. Hopefully you had a discussion upfront about the basis of design. In your case, the basis of design would have included the maximum price you were willing to pay for the pergola. If you forgot to have that discussion with your designer, now would be a good time, since it sounds like you don't like the price this pergola is going to cost. Redesigning your structure over the internet on a chat forum is going to end badly, and since by your own words you already have a designer, go back to them, explain the maximum amount of money you have available, and ask them to develop a design that meets your financial constraints.