You do not have to pay for anything but initially you will have complete medical tests, blood test, std and drug tests and a psych evaluation. The woman getting the eggs will have the same tests. I believe it is the FDA that regulates a lot of that. If it is anonymous- you will sign a contract- well in any case there should be a contract. As far as the actual donation, it will require a few weeks of injections and then the egg retrieval process. You should not be afraid of needles! During the retrieval you will have a general anesthia and they retrieve the eggs with a needle. You can google 'egg retrieval' and you will see what the procedure is like. Then you are done! I also agree with Kricket- you should make sure it is a reputable fertility clinic for your health too!
First off, I would just contact a reliable IVF clinic & they will do extensive interviewing. I mean extensive. If the motive is money they usually will really question you further. They want you to really understand what you are doing. You would be helping another person, but yet have a child in this world that you have no connection to.
I agree with Myhorse there is no pain per say for the majority. It's just a time commitment of about 10-14 days of daily injections given to yourself & constand blood withdrawel so they can monitor things including your folliciles. Good Luck to you if you decide to do this. It's really a wonderful gift you can give someone.
I am the recipient of donor eggs in Australia, my cousin has donated her eggs to me, I won't go into the legal side etc as it may not relate to your country of origin. Having tried IVF myself first with my own eggs and then again going thru it with my cousin, the pain factor is no different from slight period pain in our experience, with a little bloating, nothing that a panadol won't fix.