Hi there
This is a tricky question to answer. The best would be to contact your nearest fertility clinic to set up a meeting. There are many criteria to falling pregnant and your age may be a concern, but women of age 40 fall pregnant all the time. The specialist would be able to run some tests on both you and your partner to determine if you are both fine as far as fertility goes, what the risks of pregnancy at your age would be. You can then discuss the options you have. I have worked in the industry with egg donors and couples and I can tell you that every couple is different. They would be able to tell you costs as the costs depend on procedures that you will need as well as meds that you may need.
Good luck. x