It may seem like an obvious and silly thing to say, but something caused that fabric to wrinkle. It did not spontaneously wrinkle on its own. Unless and until you know what caused it, the price should reflect the amount of risk you're willing to assume in what repairs might be required.
It sounds like you plan on a complete recover, which the plane is definitely begging for. I would not try to get the wrinkles out and call it good unless you know what caused them in the first place .