Hey Sami,
If you are using your eggs and not your sister's then her age is not as much of an issue. My cousin is currently acting as a gestational surrogate for us and she is 48!
Our fees for the IVF were about $10,000 but then you have meds for both you and your sister which can be pretty expensive. Our lawyer's fees were about $400 for the contract and then will be about the same for the birth order. I don't know how we lucked out because other lawyer's around here charge between 2 and 3 grand for the same thing. (We live in Idaho.)
If you have more questions the BB over at
Fertilethoughts.com is pretty active with Surrogates and IP's alike. They have been very helpful and answered lots of questions for me.
Good luck on your journey. We only have a few weeks left. It's been a crazy ride, but we've made it through all right.
Rebecca